Metallus (MTUS) 10-K 25 Feb 21 2020 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2020	Feb. 15, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Trading Symbol	TMST
Title of 12(b) Security	Common shares
Security Exchange Name	NYSE
Entity Registrant Name	TIMKENSTEEL CORPORATION
Entity Central Index Key	0001598428
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Common Stock, Shares Outstanding		45,175,486
Entity Public Float			$ 160,935,221
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
ICFR Auditor Attestation Flag	true
Document Annual Report	true
Document Transition Report	false
Entity Incorporation, State or Country Code	OH
Entity Address, Address Line One	1835 Dueber Avenue SW
Entity Address, City or Town	Canton
Entity Address, State or Province	OH
City Area Code	330
Local Phone Number	471.7000
Entity Address, Postal Zip Code	44706
Entity Tax Identification Number	46-4024951
Entity File Number	1-36313
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE Document Parts Into Which Incorporated Proxy Statement for the 2021 Annual Meeting of Shareholders Part III

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Net sales	$ 830.7	$ 1,208.8	$ 1,610.6
Cost of products sold	815.1	1,186.2	1,484
Gross Profit	15.6	22.6	126.6
Selling, general and administrative expenses	76.7	91.8	98.2
Restructuring charges	3.1	8.6	0
Impairment charges and (gain) loss on sale or disposal of assets	(2.4)	9.3	0.9
Interest expense	12.2	15.7	17.1
Loss on extinguishment of debt	0.9
Other (income) expense, net	(14.2)	23.3	18.6
Income (Loss) Before Income Taxes	(60.7)	(126.1)	(8.2)
Provision (benefit) for income taxes	1.2	(16.1)	1.8
Net Income (Loss)	$ (61.9)	$ (110)	$ (10)
Per Share Data:
Basic earnings (loss) per share	$ (1.38)	$ (2.46)	$ (0.22)
Diluted earnings (loss) per share	$ (1.38)	$ (2.46)	$ (0.22)

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ (61.9)	$ (110)	$ (10)
Other comprehensive income (loss), net of tax of $0.1 million in 2020, $16.7 million in 2019 and $0.1 million in 2018:
Foreign currency translation adjustments	1.4	0.5	(1.4)
Pension and postretirement liability adjustments	(5.7)	53.1	0.1
Other comprehensive income (loss), net of tax	(4.3)	53.6	(1.3)
Comprehensive Income (Loss), net of tax	$ (66.2)	$ (56.4)	$ (11.3)

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement Of Income And Comprehensive Income [Abstract]
Other Comprehensive income (loss), tax	$ 0.1	$ 16.7	$ 0.1

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Current Assets
Cash and cash equivalents	$ 102.8	$ 27.1
Accounts receivable, net of allowances (2020 - $1.3 million; 2019 - $1.5 million)	63.3	77.5
Inventories, net	178.4	281.9
Deferred charges and prepaid expenses	4	3.3
Assets held for sale	0.3	4.1
Other current assets	8.8	7.8
Total Current Assets	357.6	401.7
Property, plant and equipment, net	569.8	626.4
Operating lease right-of-use assets	21	14.3
Pension assets	33.5	25.2
Intangible assets, net	9.3	14.3
Other non-current assets	2.8	3.3
Total Assets	994	1,085.2
Current Liabilities
Accounts payable	89.5	69.3
Salaries, wages and benefits	29.4	13.9
Accrued pension and postretirement costs	2.3	3
Current operating lease liabilities	7.5	6.2
Current convertible notes, net	38.9
Other current liabilities	13.4	19.9
Total Current Liabilities	181	112.3
Non-Current Liabilities
Non-current convertible notes, net	39.3	78.6
Credit Agreement		90
Non-current operating lease liabilities	13.5	8.2
Accrued pension and postretirement costs	240.7	222.1
Deferred income taxes	1	0.9
Other non-current liabilities	11	10
Total Liabilities	486.5	522.1
Shareholders’ Equity
Preferred shares, without par value; authorized 10.0 million shares, none issued	0	0
Common shares, without par value; authorized 200.0 million shares; issued 2020 and 2019 - 45.7 million shares	0	0
Additional paid-in capital	843.4	844.8
Retained deficit	(363.4)	(301.5)
Treasury shares - 2020 - 0.6 million; 2019 - 0.9 million	(12.9)	(24.9)
Accumulated other comprehensive income (loss)	40.4	44.7
Total Shareholders’ Equity	507.5	563.1
Total Liabilities and Shareholders’ Equity	$ 994	$ 1,085.2

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Allowances for accounts receivable	$ 1.3	$ 1.5
Preferred shares, authorized (in shares)	10,000,000	10,000,000
Preferred shares, issued (in shares)	0	0
Common shares, authorized (in shares)	200,000,000	200,000,000
Common shares, issued (in shares)	45,700,000	45,700,000
Treasury shares (in shares)	600,000	900,000

Consolidated Statements of Shar

Consolidated Statements of Shareholder's Equity - USD ($) $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Shares Outstanding	Additional Paid-in Capital	Retained Deficit	Retained DeficitCumulative Effect, Period of Adoption, Adjustment	Treasury Shares	Accumulated Other Comprehensive Income (Loss)
Beginning balance at Dec. 31, 2017	$ 616.7	$ 0.7		$ 843.7	$ (182)	$ 0.7	$ (37.4)	$ (7.6)
Beginning balance (in shares) at Dec. 31, 2017			44,445,747
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(10)				(10)
Other comprehensive income (loss)	(1.3)							(1.3)
Stock-based compensation expense	7.3			7.3
Stock option activity	0.2			0.2
Issuance of treasury shares				(4.9)	(0.2)		5.1
Issuance of treasury shares (in shares)			176,454
Shares surrendered for taxes	(0.7)						(0.7)
Shares surrendered for taxes (in shares)			(37,533)
Ending balance at Dec. 31, 2018	612.9			846.3	(191.5)		(33)	(8.9)
Ending balance (in shares) at Dec. 31, 2018			44,584,668
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(110)				(110)
Other comprehensive income (loss)	53.6							53.6
Stock-based compensation expense	7.4			7.4
Stock option activity	0.2			0.2
Issuance of treasury shares				(9.1)			9.1
Issuance of treasury shares (in shares)			321,739
Shares surrendered for taxes	(1)						(1)
Shares surrendered for taxes (in shares)			(86,254)
Ending balance at Dec. 31, 2019	563.1			844.8	(301.5)		(24.9)	44.7
Ending balance (in shares) at Dec. 31, 2019			44,820,153
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(61.9)				(61.9)
Other comprehensive income (loss)	(4.3)							(4.3)
Stock-based compensation expense	6.6			6.6
Issuance of treasury shares				(12.6)			12.6
Issuance of treasury shares (in shares)			486,260
Shares surrendered for taxes	(0.6)						(0.6)
Shares surrendered for taxes (in shares)			(142,105)
Equity component of convertible notes, net	4.6			4.6
Ending balance at Dec. 31, 2020	$ 507.5			$ 843.4	$ (363.4)		$ (12.9)	$ 40.4
Ending balance (in shares) at Dec. 31, 2020			45,164,308

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Activities
Net income (loss)	$ (61.9)	$ (110)	$ (10)
Adjustments to reconcile net loss to net cash provided (used) by operating activities:
Depreciation and amortization	70	73.5	73
Amortization of deferred financing fees and debt discount	5.3	5.1	5.5
Loss on extinguishment of debt	0.9
Impairment charges and (gain) loss on sale or disposal of assets	(2.4)	9.3	0.9
Deferred income taxes		(16.6)	0.8
Stock-based compensation expense	6.6	7.4	7.3
Pension and postretirement expense (benefit), net	8.6	41.6	37.4
Changes in operating assets and liabilities:
Accounts receivable, net	14.2	85.9	(13.6)
Inventories, net	103.5	92.6	(94.5)
Accounts payable	23.1	(87.7)	24.4
Other accrued expenses	9.4	(26)	(3.8)
Deferred charges and prepaid expenses	(0.7)	0.2	0.4
Pension and postretirement contributions and payments	(4.1)	(3.8)	(13.1)
Other, net	1	(1.2)	3.8
Net Cash Provided (Used) by Operating Activities	173.5	70.3	18.5
Investing Activities
Capital expenditures	(16.9)	(38)	(40)
Proceeds from disposals of property, plant and equipment	10.9		1
Net Cash Provided (Used) by Investing Activities	(6)	(38)	(39)
Financing Activities
Proceeds from exercise of stock options		0.2	0.2
Shares surrendered for employee taxes on stock compensation	(0.6)	(1)	(0.7)
Refunding bonds repayments			(30.2)
Repayments on credit agreements	(90)	(65)	(105)
Borrowings on credit agreements		40	155
Debt issuance costs	(1.2)	(1)	(1.7)
Net Cash Provided (Used) by Financing Activities	(91.8)	(26.8)	17.6
Increase (Decrease) in Cash and Cash Equivalents	75.7	5.5	(2.9)
Cash and cash equivalents at beginning of period	27.1	21.6	24.5
Cash and Cash Equivalents at End of Period	$ 102.8	$ 27.1	$ 21.6

Basis of Presentation

Basis of Presentation	12 Months Ended
	Dec. 31, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Basis of Presentation	Note TimkenSteel Corporation (the Company or TimkenSteel) manufactures alloy steel, as well as carbon and micro-alloy steel, with an annual melt capacity of approximately 2 million tons and shipment capacity of 1.5 million tons. TimkenSteel’s portfolio includes special bar quality (SBQ) bars, seamless mechanical tubing (tubes), value-added solutions such as precision steel components, and billets. In addition, TimkenSteel supplies machining and thermal treatment services and manages raw material recycling programs, which are also used as a feeder system for the Company’s melt operations. The Company’s products and services are used in a diverse range of demanding applications in the following market sectors: automotive; oil and gas; industrial equipment; mining; construction; rail; defense; heavy truck; agriculture; power generation; and oil country tubular goods (OCTG). The SBQ bar, tube, and billet production processes take place at the Company’s Canton, Ohio manufacturing location. This location accounts for all of the SBQ bars, seamless mechanical tubes and billets the Company produces and includes three manufacturing facilities: the Faircrest, Harrison, and Gambrinus facilities. TimkenSteel’s value-added solutions production processes take place at two downstream manufacturing facilities: Tryon Peak (Columbus, North Carolina) and St. Clair (Eaton, Ohio). Many of the production processes are integrated, and the manufacturing facilities produce products that are sold in all of the Company’s market sectors. As a result, investments in the Company’s facilities and resource allocation decisions affecting the Company’s operations are designed to benefit the overall business, not any specific aspect of the business. D Basis of Consolidation: The Consolidated Financial Statements include the consolidated assets, liabilities, revenues and expenses related to TimkenSteel as of December 31, 2020, 2019 and 2018. All significant intercompany accounts and transactions within TimkenSteel have been eliminated in the preparation of the Consolidated Financial Statements. Use of Estimates: The preparation of these Consolidated Financial Statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts reported in the Consolidated Financial Statements and accompanying notes. These estimates and assumptions are reviewed and updated regularly to reflect recent experience. Presentation: Certain items previously reported in specific financial statement captions have been reclassified to conform to the fiscal 2020 presentation.

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Significant Accounting Policies	Note Revenue Recognition: TimkenSteel recognizes revenue from contracts at a point in time when it has satisfied its performance obligation and the customer obtains control of the goods, at the amount that reflects the consideration the Company expects to receive for those goods. The Company receives and acknowledges purchase orders from its customers, which define the quantity, pricing, payment and other applicable terms and conditions. In some cases, the Company receives a blanket purchase order from its customer, which includes pricing, payment and other terms and conditions, with quantities defined at the time the customer issues periodic releases from the blanket purchase order. Certain contracts contain variable consideration, which primarily consists of rebates that are accounted for in net sales and accrued based on the estimated probability of the requirements being met. Cash Equivalents: TimkenSteel considers all highly liquid investments with a maturity of three months or less when purchased to be cash equivalents. Accounts Receivables, Net: The Company’s accounts receivables arise from sales to customers across the mobile, industrial, energy, and other end-markets. The allowance for doubtful account reserve has been established using qualitative and quantitative methods. In general, account balances greater than one year of age or sent to third party collection are fully reserved. Account balances for customers that are viewed as higher risk are also analyzed for a reserve. In addition to these methods, the allowance for doubtful accounts is adjusted for forward looking uncollectible balances based on end-market outlook and dynamics, such as in the energy and mobile end-markets in 2020. The amount recorded was based on the Company’s assessment of the risk presented by customers in these end - markets as a result of the COVID-19 pandemic as well as geo-political factors facing the energy end - market. Historically, TimkenSteel’s allowance for doubtful accounts write-offs have been immaterial. Inventories, Net: Inventories are stated at lower of cost or net realizable value. All inventories, including raw materials, manufacturing supplies inventory as well as international (outside the U.S.) inventories, have been valued using the FIFO or average cost method as of December 31, 2020 and 2019. Property, Plant and Equipment, Net: Property, plant and equipment, net are valued at cost less accumulated depreciation. Maintenance and repairs are charged to expense as incurred. The provision for depreciation is computed principally by the straight-line method based upon the estimated useful lives of the assets. The useful lives are approximately 30 years for buildings and three to 20 years for machinery and equipment. Intangible Assets, Net: Intangible assets subject to amortization are amortized on a straight-line method over their legal or estimated useful lives, with useful lives ranging from 3 to 15 years. In accordance with applicable accounting guidance, TimkenSteel capitalizes certain costs incurred for computer software developed or obtained for internal use. TimkenSteel capitalizes substantially all external costs and qualifying internal costs related to the purchase and implementation of software projects used for business operations. Capitalized software costs primarily include purchased software and external consulting fees. Capitalized software projects are amortized over the estimated useful lives of the software. Long-lived Assets: Long-lived assets (including tangible assets and intangible assets subject to amortization) are reviewed for impairment when events or changes in circumstances have occurred indicating that the carrying value of the assets may not be recoverable. TimkenSteel tests recoverability of long-lived assets at the lowest level for which there are identifiable cash flows that are independent from the cash flows of other assets. Assets and asset groups held and used are measured for recoverability by comparing the carrying amount of the asset or asset group to the sum of future undiscounted net cash flows expected to be generated by the asset or asset group. Assumptions and estimates about future values and remaining useful lives of TimkenSteel’s long-lived assets are complex and subjective. They can be affected by a variety of factors, including external factors such as industry and economic trends and internal factors such as changes in TimkenSteel’s business strategy and internal forecasts. If an asset or asset group is considered to be impaired, the impairment loss that would be recognized is the amount by which the carrying amount of the assets exceeds the fair value of the assets. To determine fair value, TimkenSteel uses internal cash flow estimates discounted at an appropriate interest rate, third party appraisals, as appropriate, and/or market prices of similar assets, when available. Refer to “Note 6 - Disposition of Non-Core Assets” and “Note 11 - Property, Plant and Equipment” for additional information. Product Warranties: TimkenSteel accrues liabilities for warranties based upon specific claim incidents in accordance with accounting rules relating to contingent liabilities. Should TimkenSteel become aware of a specific potential warranty claim for which liability is probable and reasonably estimable, a specific charge is recorded and accounted for accordingly. TimkenSteel had no significant warranty claims for the years ended December 31, 2020, 2019 or 2018. Income Taxes: Deferred tax assets and liabilities are recorded for the future tax consequences attributable to differences between financial statement carrying amounts of existing assets and liabilities and their respective tax bases, as well as net operating loss and tax credit carryforwards. TimkenSteel accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined on the basis of the differences between the financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. TimkenSteel recognizes deferred tax assets to the extent TimkenSteel believes these assets are more likely than not to be realized. In making such a determination, TimkenSteel considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. If TimkenSteel determines that it would be able to realize deferred tax assets in the future in excess of their net recorded amount, TimkenSteel would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. TimkenSteel records uncertain tax positions in accordance with applicable accounting guidance , on the basis of a two-step process whereby (1) TimkenSteel determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position, and (2) for those tax positions that meet the more-likely-than-not recognition threshold, TimkenSteel recognizes the largest amount of tax benefit that is more than 50 percent likely to be realized upon ultimate settlement with the related tax authority. TimkenSteel recognizes interest and penalties related to unrecognized tax benefits within the provision (benefit) for income taxes line in the accompanying Consolidated Statements of Operations. Accrued interest and penalties are included within the related tax liability line in the Consolidated Balance Sheets. The Company made the accounting policy election to treat taxes related to Global Intangible Low-Taxed Income (GILTI) as a current period expense when incurred. Foreign Currency: Assets and liabilities of subsidiaries are translated at the rate of exchange in effect on the balance sheet date. Income and expenses are translated at the average rates of exchange prevailing during the year. The related translation adjustments are reflected as a separate component of accumulated other comprehensive loss. Gains and losses resulting from foreign currency transactions are included in other (income) expense, net in the Consolidated Statements of Operations. TimkenSteel realized a foreign currency exchange loss of $0.2 Pension and Other Postretirement Benefits: TimkenSteel recognizes an overfunded status or underfunded status (e.g., the difference between the fair value of plan assets and the benefit obligations) as either an asset or a liability for its defined benefit pension and other postretirement benefit plans on the Consolidated Balance Sheets. The Company recognizes actuarial gains and losses immediately through net periodic benefit cost in the Consolidated Statements of Operations upon the annual remeasurement at December 31, or on an interim basis as triggering events warrant remeasurement. In addition, the Company uses fair value to account for the value of plan assets. Stock-Based Compensation: TimkenSteel recognizes stock-based compensation expense based on the grant date fair value of the stock-based awards over their required vesting period on a straight-line basis, whether the awards were granted with graded or cliff vesting. Stock options are issued with an exercise price equal to the closing market price of TimkenSteel common shares on the date of grant. The fair value of stock options is determined using a Black-Scholes option pricing model, which incorporates assumptions regarding the expected volatility, the expected option life, the risk-free interest rate and the expected dividend yield. Performance-vested restricted stock units issued in 2020 vest based on achievement of a total shareholder return (TSR) metric. The TSR metric is considered a market condition, which requires TimkenSteel to reflect it in the fair value on grant date using an advanced option-pricing model. The fair value of each performance share was therefore determined using a Monte Carlo valuation model, a generally accepted lattice pricing model. The Monte Carlo valuation model, among other factors, uses commonly-accepted economic theory underlying all valuation models, estimates fair value using simulations of future share prices based on stock price behavior and considers the correlation of peer company returns in determining fair value. The fair value of stock-based awards that will settle in TimkenSteel common shares, other than stock options and performance-vested restricted stock units, is based on the closing market price of TimkenSteel common shares on the grant date. The fair values of stock-based awards that will settle in cash are remeasured at each reporting period until settlement of the awards. TimkenSteel recognizes all excess tax benefits and tax deficiencies as income tax expense or benefit in the Consolidated Statements of Operations. The excess tax benefits and tax deficiencies are considered discrete items in the reporting period they occur and are not included in the estimate of an entity’s annual effective tax rate. Research and Development: Expenditures for TimkenSteel research and development amounted to $1.8 million for the year ended December 31, 2020, $4.1 million for the year ended December 31, 2019 and $8.1 million for the year ended December 31, 2018, and were recorded as a component of selling, general and administrative expenses in the Consolidated Statements of Operations. These expenditures may fluctuate from year to year depending on special projects and the needs of TimkenSteel and its customers. Adoption of New Accounting Standards The Company adopted the following Accounting Standard Updates (ASU) during the year ended December 31, 2020. The adoption of these standards did not have a material impact on the Consolidated Financial Statements or the related Notes to the Consolidated Financial Statements. Standards Adopted Description Date of Adoption ASU 2016-13, Measurement of Credit Losses on Financial Instruments (Topic 326) The standard changes how entities will measure credit losses for most financial assets, including trade and other receivables, and replaces the current incurred loss approach with an expected loss model. January 1, 2020 ASU 2018-13, Fair Value Measurement (Topic 820) The standard eliminates, modifies and adds disclosure requirements for fair value measurements. January 1, 2020 ASU 2018-14, Compensation - Retirement Benefits - Defined Benefit Plans - General (Subtopic 715-20) The standard eliminates, modifies and adds disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. January 1, 2020 ASU 2018-15, Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40) The standard aligns the requirements for capitalizing implementation costs in cloud computing software arrangements with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. January 1, 2020 ASU 2020-04, Reference Rate Reform (Topic 848) The standard provides optional expedients and exceptions for applying generally accepted accounting principles to contracts, hedging relationships and other transactions affected by reference rate reform if certain criteria are met. March 12, 2020 Accounting Standards Issued But Not Yet Adopted The Company has considered the recent ASUs issued by the Financial Accounting Standards Board summarized below: Standard Pending Adoption Description Effective Date Anticipated Impact ASU 2019-12, Income Taxes (Topic 740) The standard simplifies the accounting for income taxes by removing various exceptions. January 1, 2021 The Company has evaluated the impact of adopting of this ASU and it will not have a material impact on the Consolidated Financial Statements. ASU 2020-06, Debt - Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging - Contracts in Entity’s Own Equity (Subtopic 815-40) The standard simplifies the accounting for convertible instruments, as well as the diluted net income per share calculation. The standard also removes certain settlement conditions that are required for equity contracts to qualify for the derivative scope exception. The amendments in the standard are effective for fiscal years beginning after December 15, 2021, however early adoption is permitted for fiscal years beginning after December 15, 2020. Entities can adopt the guidance through either a modified retrospective method of transition or a fully retrospective method of transition. January 1, 2021 (Early Adoption Date) The Company has elected to early adopt this standard as of January 1, 2021 using the modified retrospective method of transition. We expect this standard will have a material impact on the Consolidated Financial Statements. Refer to “Note 14 – Financing Arrangements” for additional information.

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Segment Information	Note We conduct our business activities and report financial results as one business segment. The presentation of financial results as one reportable segment is consistent with the way the Company operates its business and is consistent with the manner in which the Chief Operating Decision Maker (CODM) evaluates performance and makes resource and operating decisions for the business as described above. Furthermore, the Company notes that monitoring financial results as one reportable segment helps the CODM manage costs on a consolidated basis, consistent with the integrated nature of the operations. Geographic Information Net sales by geographic area are reported by the country in which the customer is domiciled. Long-lived assets include property, plant and equipment and intangible assets subject to amortization. Long-lived assets by geographic area are reported by the location of the TimkenSteel operations to which the asset is attributed. Year Ended December 31, 2020 2019 2018 Net Sales: United States $ 746.8 $ 1,096.8 $ 1,456.2 Foreign 83.9 112.0 154.4 $ 830.7 $ 1,208.8 $ 1,610.6 December 31, 2020 2019 Long-lived Assets, net: United States $ 599.1 $ 654.8 Foreign 1.0 0.2 $ 600.1 $ 655.0

Revenue Recognition

Revenue Recognition	12 Months Ended
	Dec. 31, 2020
Revenue From Contract With Customer [Abstract]
Revenue Recognition	Note The following table provides the major sources of revenue by end-market sector for the years ended December 31, 2020, 2019 and 2018: Year Ended December 31, 2020 2019 2018 Mobile $ 346.0 $ 479.3 $ 553.9 Industrial 391.7 486.3 637.5 Energy 53.2 166.4 265.6 Other ( 1) 39.8 76.8 153.6 Total Net Sales $ 830.7 $ 1,208.8 $ 1,610.6 (1) “Other” for sales by end-market sector includes the Company’s scrap and OCTG billet sales. The following table provides the major sources of revenue by product type for the years ended December 31, 2020, 2019 and 2018: Year Ended December 31, 2020 2019 2018 Bar $ 502.5 $ 783.0 $ 1,030.7 Tube 101.4 151.8 254.7 Value-add 208.1 240.6 284.3 Other ( 2) 18.7 33.4 40.9 Total Net Sales $ 830.7 $ 1,208.8 $ 1,610.6 (2) “Other” for sales by product type includes the Company’s scrap sales.

Restructuring Charges

Restructuring Charges	12 Months Ended
	Dec. 31, 2020
Restructuring And Related Activities [Abstract]
Restructuring Charges	Note During 2019 and throughout 2020, TimkenSteel made organizational changes to streamline its organizational structure to drive enhanced profitability and sustainable growth. These company-wide actions included the restructuring of its business support functions, the reduction of management layers throughout the organization, the closure of the TimkenSteel Material Services (TMS) facility in Houston, Texas and other domestic and international actions to further improve the Company’s overall cost structure. Through these restructuring efforts, to date the Company has eliminated approximately 215 salaried positions and recognized restructuring charges of $3.1 million in 2020 and $8.6 million in 2019 The following is a summary of the restructuring reserve for the twelve months ended December 31, 2020 and 2019: Balance at December 31, 2019 $ 6.0 Expenses (1) 3.1 Payments (7.6 ) Balance at December 31, 2020 $ 1.5 (1) Expenses of $3.1 million exclude stock compensation of $0.1 million that was accelerated as a result of the Company’s restructuring activities. Balance at December 31, 2018 $ — Expenses (2) 8.6 Payments (2.6 ) Balance at December 31, 2019 $ 6.0 (2) Expenses of $8.6 million exclude stock compensation of $0.3 million that was accelerated as a result of the Company’s restructuring activities. There were no restructuring charges for the year ended December 31, 2018.

Disposition of Non-Core Assets

Disposition of Non-Core Assets	12 Months Ended
	Dec. 31, 2020
Discontinued Operations And Disposal Groups [Abstract]
Disposition of Non-Core Assets	Note 6 - Disposition of Non-Core Assets Scrap Processing Facility During the fourth quarter of 2019, management signed a letter of intent to dispose of the Company’s scrap processing facility in Akron, Ohio for cash consideration of approximately $4.0 million. This letter of intent and cash consideration were for the land, buildings, machinery and equipment associated with this facility. As a result of the agreement to sell the scrap processing facility, the Company ceased depreciation of the assets and recorded them as assets held for sale on the Consolidated Balance Sheets as of December 31, 2019. This disposal does not represent a discontinued operation. Additionally, the Company recorded an impairment charge of $7.3 million in the fourth quarter of 2019 which represents the cash consideration to be received less cost to sell the assets compared with the $11.3 million carrying value of the assets being sold, including supplies inventory. An additional loss on disposal of $0.1 million was recognized in the first quarter of 2020 as the sale was completed. TimkenSteel Material Services Facility D uring the first quarter of 2020, management completed its previously announced plan to close the Company’s TMS facility in Houston and began selling the assets at the facility. Accelerated depreciation and amortization on TMS assets of $2.8 million was recorded in the fourth quarter of 2019, with an additional $1.6 million of accelerated depreciation and amortization recorded in the first quarter of 2020, to reduce the net book value of the machinery and equipment to its estimated fair value. Subsequent to the closure, certain assets were sold and a gain on sale of $3.6 million was recognized for the year ended December 31, 2020. At December 31, 2020, the remaining associated machinery and equipment, with a net book value of $0.3 million, was classified as held for sale on the Consolidated Balance Sheets. The land and buildings associated with TMS were not classified as held for sale, as they were not considered available for immediate sale in their present condition. Inventory write-downs of $4.8 million were recorded as of December 31, 2019, which represented the difference between the expected selling price and carrying value of the related inventory. The expected selling price was based upon the Company’s most recently published price lists related to this inventory. While the Company began selling the inventory associated with TMS in the first quarter of 2020 at prices that were in line with the net realizable value of the inventory established in the fourth quarter of 2019, excess inventory related to the energy end-market sector resulted in an additional reserve of approximately $3.1 million being recorded in the second quarter of 2020. The excess inventory is the result of continued weakness in this end-market sector, as well as recent closures of several distributors that were holding considerable amounts of similar inventory. Small-Diameter Seamless Mechanical Tubing Machinery and Equipment In the third quarter of 2020, TimkenSteel informed customers that as of December 31, 2020 the Company will discontinue the commercial offering of specific small-diameter seamless mechanical tubing product offerings. As a result, the Company recognized accelerated depreciation of $1.8 million for the year ended December 31, 2020 on the machinery and equipment used in the manufacturing of these specific products. Additional accelerated depreciation of $1.3 million will be recognized in the first quarter of 2021 in alignment with the ramp down of this machinery and equipment. Property Sales In the fourth quarter of 2020, TimkenSteel sold portions of non-core property at the Canton, Ohio manufacturing location, resulting in a gain on sale of assets of $0.5 million for the year ended December 31, 2020.

Other (Income) Expense, Net

Other (Income) Expense, Net	12 Months Ended
	Dec. 31, 2020
Other Income And Expenses [Abstract]
Other (Income) Expense, Net	Note The following table provides the components of other (income) expense, net for the years ended December 31, 2020, 2019 and 2018: Year Ended December 31, 2020 2019 2018 Pension and postretirement non-service benefit (income) loss $ (26.6 ) $ (17.5 ) $ (25.2 ) Loss (gain) from remeasurement of benefit plans 14.7 40.6 43.5 Foreign currency exchange loss (gain) 0.2 — 0.2 Employee retention credit (2.3 ) — — Miscellaneous (income) expense (0.2 ) 0.2 0.1 Total other (income) expense, net $ (14.2 ) $ 23.3 $ 18.6 Non-service related pension and other postretirement benefit income, for all years, consists primarily of the interest cost, expected return on plan assets and amortization components of net periodic cost. The loss from remeasurement of benefit plans is due to the Company performing mark-to-market accounting on its pension and postretirement assets at year-end and upon the occurrence of certain triggering events . Coronavirus Aid, Relief, and Economic Security ("CARES") Act On March 27, 2020, the President of the United States signed the Coronavirus Aid, Relief, and Economic Security ("CARES") Act, an economic stimulus package intended to provide support, principally in the form of tax benefits, to companies and individuals negatively impacted by the COVID-19 pandemic. Although the majority of the provisions included in the CARES Act did not immediately benefit the Company from a cash tax perspective due to its significant net operating losses, the Company has taken advantage of the deferral of the employer share (6.2% of employee wages) of Social Security payroll taxes that would otherwise have been owed from the date of enactment of the legislation through December 31, 2020, as afforded by the Act. Through December 31, 2020, the Company has deferred $6.4 million in cash payments and recorded reserves for such deferred payroll taxes in salaries, wages and benefits on the Consolidated Balance Sheets. The deferred amount of payments is to be paid in two equal installments at December 31, 2021 and December 31, 2022. The CARES Act also provided for an employee retention credit (“Employee Retention Credit”), which is a refundable tax credit against certain employment taxes of up to $5,000 per employee for eligible employers. The tax credit is equal to 50% of qualified wages paid to employees during a quarter, capped at $10,000 of qualified wages per employee throughout the year. The Company qualified for the tax credit in the second and third quarters of 2020 and accrued a benefit of $2.3 million in the fourth quarter of 2020 related to the Employee Retention Credit in other (income) expense, net on the Company’s Consolidated Statements of Operations.

Income Tax Provision

Income Tax Provision	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Tax Provision	Note Income (loss) from operations before income taxes, based on geographic location of the operations to which such earnings are attributable, is provided below. Years Ended December 31, 2020 2019 2018 United States $ (64.1 ) $ (130.8 ) $ (10.1 ) Non-United States 3.4 4.7 1.9 Loss from operations before income taxes $ (60.7 ) $ (126.1 ) $ (8.2 ) The provision (benefit) for income taxes consisted of the following: Years Ended December 31, 2020 2019 2018 Current: Federal $ 0.6 $ — $ — State and local — 0.1 0.3 Foreign 0.5 0.4 0.7 Total current tax expense (benefit) $ 1.1 $ 0.5 $ 1.0 Deferred: Federal $ (0.4 ) $ (14.4 ) $ 0.4 State and local 0.5 (2.0 ) — Foreign — (0.2 ) 0.4 Total deferred tax expense (benefit) 0.1 (16.6 ) 0.8 Provision (benefit) for incomes taxes $ 1.2 $ (16.1 ) $ 1.8 For the year ended December 31, 2020, TimkenSteel made $0.4 million in foreign tax payments, $0.1 million in state tax payments, and no U.S. federal payments, and had no refundable overpayments of state income taxes. For the year ended December 31, 2019, TimkenSteel made $0.6 million in foreign tax payments, $0.2 million in state tax payments, and no U.S. federal payments, and had no refundable overpayments of state income taxes. The reconciliation between TimkenSteel’s effective tax rate on income (loss) from continuing operations and the statutory tax rate is as follows: Years Ended December 31, 2020 2019 2018 U.S. federal income tax provision (benefit) at statutory rate $ (12.7 ) $ (26.5 ) $ (6.3 ) Adjustments: State and local income taxes, net of federal tax benefit 2.3 (1.3 ) (0.5 ) Foreign earnings taxed at different rates 0.1 — 0.2 U.S. research tax credit — 0.2 (0.2 ) Valuation allowance 10.3 10.2 7.5 Global intangible low-taxed income — 0.2 0.5 Permanent differences 1.3 1.3 0.8 Other items, net (0.1 ) (0.2 ) (0.2 ) Provision (benefit) for income taxes $ 1.2 $ (16.1 ) $ 1.8 Effective tax rate (2.0 )% 12.8 % (5.9 )% Income tax expense includes U.S. and international income taxes. Except as required under U.S. tax law, U.S. income and foreign withholding taxes have not been recognized on the excess of the amount for financial reporting over the tax basis of investments in foreign subsidiaries that is indefinitely reinvested outside the U.S. This amount becomes taxable upon a repatriation of assets from the subsidiary or a sale or liquidation of the subsidiary. During the third quarter of 2020, TimkenSteel (Shanghai) Corporation Limited declared a dividend of $5.1 million to TimkenSteel. Foreign withholding taxes paid on this repatriation of previous profits were $0.5 million, resulting in $4.6 million of cash sent to the U.S. Undistributed earnings of foreign subsidiaries outside of the U.S. were $2.7 million, $6.5 million and $5.5 million at December 31, 2020, 2019 and 2018, respectively. The Company has recognized a deferred tax liability in the amount of $0.3 million and $0.7 million at December 31, 2020 and 2019, respectively, for undistributed earnings at its TimkenSteel (Shanghai) Corporation Limited and TimkenSteel de Mexico S. de R.C. de C.V. subsidiaries, as those earnings are not permanently reinvested by the Company. The effect of temporary differences giving rise to deferred tax assets and liabilities at December 31, 2020 and 2019 was as follows: December 31, 2020 2019 Deferred tax liabilities: Depreciation $ (97.5 ) $ (98.6 ) Inventory (16.2 ) (24.3 ) Convertible debt (1.6 ) (1.7 ) Leases - right-of-use asset (5.0 ) (3.4 ) Other, net (0.3 ) (0.7 ) Deferred tax liabilities $ (120.6 ) $ (128.7 ) Deferred tax assets: Pension and postretirement benefits $ 50.3 $ 47.9 Other employee benefit accruals 8.7 7.2 Tax loss carryforwards 94.4 86.0 Intangible assets 1.0 1.1 Inventory 4.5 5.4 State decoupling 2.8 4.5 Lease liability 5.0 3.4 Interest limitation — 6.0 Other, net 0.6 1.2 Deferred tax assets subtotal $ 167.3 $ 162.7 Valuation allowances (47.7 ) (34.9 ) Deferred tax assets 119.6 127.8 Net deferred tax assets (liabilities) $ (1.0 ) $ (0.9 ) As of December 31, 2020 and 2019, the Company had a deferred tax liability of $1.0 million and $0.9 million, respectively, on the Consolidated Balance Sheets. As of December 31, 2020, TimkenSteel had loss carryforwards in the U.S. and various non-U.S. jurisdictions totaling $406.8 million (of which $348.3 million relates to the U.S. and $58.5 million relates to the UK jurisdiction), having various expiration dates. TimkenSteel has provided valuation allowances of $47.7 million against these carryforwards. The majority of the non-U.S. loss carryforwards represent local country net operating losses for branches of TimkenSteel or entities treated as branches of TimkenSteel under U.S. tax law. Tax benefits have previously been recorded for these losses in the U.S. The related local country net operating loss carryforwards are offset fully by valuation allowances. During 2016, operating losses generated in the U.S. resulted in a decrease in the carrying value of the Company’s U.S. deferred tax liability to the point that would result in a net U.S. deferred tax asset at December 31, 2016. In light of TimkenSteel’s operating performance in the U.S. and current industry conditions, the Company assessed, based upon all available evidence, and concluded that it was more likely than not that it would not realize a portion of its U.S. deferred tax assets. The Company recorded a valuation allowance in 2016 and as a result of current year activity, the Company remained in a full valuation allowance position through 2020. Going forward, the need to maintain valuation allowances against deferred tax assets in the U.S. and other affected countries will cause variability in the Company’s effective tax rate. The Company will maintain a valuation allowance against its deferred tax assets in the U.S. and applicable foreign countries until sufficient positive evidence exists to eliminate them. As of December 31, 2020, 2019 and 2018, TimkenSteel had no total gross unrecognized tax benefits, and no amounts which represented unrecognized tax benefits that would favorably impact TimkenSteel’s effective income tax rate in any future periods if such benefits were recognized. As of December 31, 2020, TimkenSteel does not anticipate a change in its unrecognized tax positions during the next 12 months. TimkenSteel had no accrued interest and penalties related to uncertain tax positions as of December 31, 2020, 2019 and 2018. As of December 31, 2020, TimkenSteel is not subject to examination by the IRS. Pursuant to the Tax Sharing Agreement dated June 30, 2014 between TimkenSteel and The Timken Company, TimkenSteel may be subject to results from tax examinations for The Timken Company for federal, state and local and various foreign tax jurisdictions in various open audit periods. Consolidated Appropriations Act of 2021 On December 27, 2020 the Consolidated Appropriations Act of 2021 (“the Appropriations Act”) was signed into law. The Appropriations Act, among other things includes provisions related to the deductibility of paycheck protection program (“PPP”) expenses paid with PPP loan proceeds, payroll tax credits, modifications to the meals and entertainment deduction, increased limitations on charitable deductions for corporate taxpayers, and enhancements of expiring tax “extender” provisions. The Company has completed its assessment of the impact of the legislation, and there is no significant impact to the Consolidated Financial Statements.

Earnings (Loss) Per Share

Earnings (Loss) Per Share	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Earnings (Loss) Per Share	Note 9 - Earnings (Loss) Per Share Basic loss per share is computed based upon the weighted average number of common shares outstanding. Diluted loss per share is computed based upon the weighted average number of common shares outstanding plus the dilutive effect of common share equivalents calculated using the treasury stock method or if-converted method. For the Convertible Notes, the Company utilizes the if-converted method to calculate diluted loss per share. Under the if-converted method, the Company adjusts net earnings to add back interest expense (including amortization of debt discount) recognized on the Convertible Notes and includes the number of shares potentially issuable related to the Convertible Notes in the weighted average shares outstanding. Treasury stock is excluded from the denominator in calculating both basic and diluted loss per share. For the years ended December 31, 2020, 2019 and 2018, 4.6 million, 3.7 million, and 3.3 million shares issuable for equity-based awards, respectively, were excluded from the computation of diluted loss per share because the effect of their inclusion would have been anti-dilutive. The shares potentially issuable related to the Convertible Notes for the years ended December 31, 2020, 2019, and 2018 of 9.1 million, 6.9 million, and 6.9 million, respectively, were also anti-dilutive and therefore excluded from the computation of diluted loss per share. The following table sets forth the reconciliation of the numerator and the denominator of basic and diluted loss per share for the years ended December 31, 2020, 2019 and 2018: Year Ended December 31, 2020 2019 2018 Numerator: Net income (loss) $ (61.9 ) $ (110.0 ) $ (10.0 ) Denominator: Weighted average shares outstanding, basic 45.0 44.8 44.6 Weighted average shares outstanding, diluted 45.0 44.8 44.6 Basic earnings (loss) per share $ (1.38 ) $ (2.46 ) $ (0.22 ) Diluted earnings (loss) per share $ (1.38 ) $ (2.46 ) $ (0.22 )

Inventories

Inventories	12 Months Ended
	Dec. 31, 2020
Inventory Disclosure [Abstract]
Inventories	Note The components of inventories as of December 31, 2020 and 2019 were as follows: December 31, 2020 2019 Manufacturing supplies $ 37.6 $ 49.8 Raw materials 20.0 26.0 Work in process 79.1 123.7 Finished products 55.6 93.1 Gross inventory 192.3 292.6 Allowance for inventory reserves (13.9 ) (10.7 ) Total inventories, net $ 178.4 $ 281.9 In connection with the closure of TMS, the Company recorded an additional reserve against inventory of $4.8 million in 2019 and increased this reserve by $3.1 million in the second quarter of 2020 to state it at the lower of cost or net realizable value. See “Note 6 - Disposition of Non-Core Assets.”

Property, Plant and Equipment

Property, Plant and Equipment	12 Months Ended
	Dec. 31, 2020
Property Plant And Equipment [Abstract]
Property, Plant and Equipment	Note The components of property, plant and equipment, net as of December 31, 2020 and 2019 were as follows: December 31, 2020 2019 Land $ 13.3 $ 13.3 Buildings and improvements 422.5 419.0 Machinery and equipment 1,398.7 1,404.6 Construction in progress 11.0 30.9 Subtotal 1,845.5 1,867.8 Less allowances for depreciation (1,275.7 ) (1,241.4 ) Property, plant and equipment, net $ 569.8 $ 626.4 Total depreciation expense was $65.0 million, $67.4 million, and $67.5 million for the years ended December 31, 2020, 2019, and 2018 respectively. Depreciation expense for the years ended December 31, 2020 and 2019 includes $2.4 million and $1.9 million, respectively, of accelerated depreciation related to the closure of TMS which was announced in the fourth quarter of 2019 and the discontinuation of specific small-diameter seamless mechanical tube manufacturing announced in 2020. See “Note 6 - Disposition of Non-Core Assets” for additional information. For the year ended December 31, 2020, TimkenSteel recorded a net gain on the sale and disposal of assets of $2.6 million, primarily related to the sale of certain TMS assets. For the year ended December 31, 2019, TimkenSteel recorded impairments and loss on disposal of assets of $9.0 million primarily related to the abandonment of certain equipment and the impairment of assets held for sale. For the year ended December 31, 2018, TimkenSteel recorded approximately $0.5 of impairment charges and loss on sale or disposal of assets related to the discontinued use of certain assets.

Intangible Assets

Intangible Assets	12 Months Ended
	Dec. 31, 2020
Goodwill And Intangible Assets Disclosure [Abstract]
Intangible Assets	Note The components of intangible assets, net as of December 31, 2020 and 2019 were as follows: December 31, 2020 December 31, 2019 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Customer relationships $ 6.3 $ 5.4 $ 0.9 $ 6.3 $ 5.0 $ 1.3 Technology use 9.0 9.0 — 9.0 8.0 1.0 Capitalized software 58.0 49.6 8.4 61.1 49.1 12.0 Total intangible assets $ 73.3 $ 64.0 $ 9.3 $ 76.4 $ 62.1 $ 14.3 Intangible assets subject to amortization are amortized on a straight-line method over their legal or estimated useful lives. The weighted average useful lives of the customer relationships, technology use and capitalized software intangible assets are 15 years, 15 years and 6 years, respectively. The weighted average useful life of total intangible assets is 8 years. Amortization expense for intangible assets for the years ended December 31, 2020, 2019, and 2018 was $5.0 million, $6.1 million and $5.5 million, respectively. Amortization expense in 2020 and 2019 associated with capitalized software includes accelerated amortization of $1.0 million and $0.9 million, respectively, related to the closure of TMS. See “Note 6 - Disposition of Non-Core Assets” for additional information. During the years ended December 31, 2020, 2019, and 2018, TimkenSteel recorded a loss on disposal of $0.2 million, $0.1 million, and $0.4 million, respectively, related to capitalized software. Based upon the intangible assets subject to amortization as of December 31, 2020, TimkenSteel’s estimated annual amortization for the five succeeding years is shown below (in millions): Year Amortization Expense 2021 $ 3.1 2022 2.6 2023 2.0 2024 1.0 2025 0.1

Leases

Leases	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Leases	Note The Company has operating leases for office space, warehouses, land, machinery and equipment, vehicles and certain information technology equipment. These leases have remaining lease terms of less than one year to six years, some of which may include options to extend the leases for one or more years. Certain leases also include options to purchase the leased property. As of December 31, 2020, the Company has no financing leases. The weighted average remaining lease term for our operating leases as of December 31, 2020 was 3.4 years. Leases with an initial term of 12 months or less (short-term leases) are not recorded on the balance sheet. Rather, the Company recognizes lease expense for these leases on a straight-line basis over the lease term in accordance with the applicable accounting guidance. For lease agreements entered into after the adoption of lease accounting guidance on January 1, 2019, the Company combines lease and non-lease components. The Company’s lease agreements do not contain material residual value guarantees or material restrictive covenants. The Company recorded lease cost for the year ended December 31, 2020 as follows: Year Ended December 31, 2020 2019 Operating lease cost $ 8.8 $ 7.4 Short-term lease cost 0.7 1.9 Total lease cost $ 9.5 $ 9.3 When available, the rate implicit in the lease is used to discount lease payments to present value; however, the Company’s leases generally do not provide a readily determinable implicit rate. Therefore, the incremental borrowing rate to discount the lease payments is estimated using market-based information available at lease commencement. The weighted average discount rate used to measure our operating lease liabilities as of December 31, 2020 was 3.2%. Supplemental cash flow information related to leases was as follows: Year Ended December 31, 2020 2019 Cash paid for amounts included in the measurement of operating lease liabilities $ 8.8 $ 7.5 Right-of-use assets obtained in exchange for operating lease obligations $ 12.5 $ 4.3 Future minimum lease payments under non-cancellable leases as of December 31, 2020 were as follows: 2021 $ 8.4 2022 5.7 2023 4.8 2024 2.7 After 2024 0.9 Total future minimum lease payments 22.5 Less amount of lease payment representing interest (1.5 ) Total present value of lease payments $ 21.0 As of December 31, 2020, we do not have any significant operating leases that have not yet commenced.

Financing Arrangements

Financing Arrangements	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Financing Arrangements	Note The following table summarizes the current and non-current debt as of December 31, 2020 and 2019: Year Ended December 31, 2020 2019 Credit Agreement $ — $ 90.0 Convertible Senior Notes due 2021 38.9 78.6 Convertible Senior Notes due 2025 39.3 0.0 Total debt $ 78.2 $ 168.6 Less current portion of debt 38.9 — Total non-current portion of debt $ 39.3 $ 168.6 Amended Credit Agreement On October 15, 2019, the Company, as borrower, and certain domestic subsidiaries of the Company, as subsidiary guarantors, entered into a Third Amended and Restated Credit Agreement (the Amended Credit Agreement), with JP Morgan Chase Bank, N.A., as administrative agent (the Administrative Agent), Bank of America, N.A., as syndication agent, and the other lenders party thereto (collectively, the Lenders), which further amended and restated the Company’s existing Credit Agreement dated as of January 26, 2018. The Amended Credit Agreement provides for a $400.0 million asset-based revolving credit facility (the Credit Facility), including a $15.0 million sublimit for the issuance of commercial and standby letters of credit and a $40.0 million sublimit for swingline loans. Pursuant to the terms of the Amended Credit Agreement, the Company is entitled, on up to two occasions and subject to the satisfaction of certain conditions, to request increases in the commitments under the Amended Credit Agreement in the aggregate principal amount of up to $100.0 million, to the extent that existing or new lenders agree to provide such additional commitments. In addition to, and independent of any increase described in the preceding sentence, the Company is entitled, subject to the satisfaction of certain conditions, to request a separate first-in, last-out (FILO) tranche in an aggregate principal amount of up to $30.0 million with a separate borrowing base and interest rate margins, in each case, to be agreed upon among the Company, the Administrative Agent and the Lenders providing the incremental FILO tranche. The availability of borrowings under the Credit Facility is subject to a borrowing base calculation based upon a valuation of the eligible accounts receivable, inventory and machinery and equipment of the Company and the subsidiary guarantors, each multiplied by an applicable advance rate. The availability of borrowings may be further modified by reserves established from time to time by the Administrative Agent in its permitted discretion. The interest rate per annum applicable to loans under the Credit Facility will be, at the Company’s option, equal to either (i) the alternate base rate plus the applicable margin or (ii) the relevant adjusted LIBO rate for an interest period of one, two, three or six months (as selected by the Company) plus the applicable margin. The base rate will be a fluctuating rate per annum equal to the greatest of ( i ) the prime rate as quoted in The Wall Street Journal, (ii) the effective Federal Reserve Bank of New York rate plus 0.50 % and (iii) the adjusted LIBO rate for a one-month interest period on the applicable date, plus 1.00% . The adjusted LIBO rate will be equal to the applicable London interbank offered rate for the selected interest period, as adjusted for statutory reserve requirements for eurocurrency liabilities. The applicable margin will be determined by a pricing grid based on the Company’s average quarterly availability. In addition, the Company will pay a 0.25% per annum commitment fee on the average daily unused amount of the Credit Facility. As of December 31, 2020, t he amount available under the Amended Credit Agreement was $ 211.3 million , reflective of the Company’s asset borrowing base with no outstanding borrowings . All of the indebtedness under the Credit Facility is guaranteed by the Company’s material domestic subsidiaries, as well as any other domestic subsidiary that the Company elects to make a party to the Amended Credit Agreement, and is secured by substantially all of the personal property of the Company and the subsidiary guarantors. The Credit Facility matures on October 15, 2024. Prior to the maturity date, amounts outstanding are required to be repaid (without reduction of the commitments thereunder) from mandatory prepayment events from the proceeds of certain asset sales, equity or debt issuances or casualty events. The Amended Credit Agreement contains certain customary covenants, including covenants that limit the ability of the Company and its subsidiaries to, among other things, (i) incur or suffer to exist certain liens, (ii) make investments, (iii) incur or guaranty additional indebtedness, (iv) enter into consolidations, mergers, acquisitions, sale-leaseback transactions and sales of assets, (v) make distributions and other restricted payments, (vi) change the nature of its business, (vii) engage in transactions with affiliates and (viii) enter into restrictive agreements, including agreements that restrict the ability to incur liens or make distributions. In addition, the Amended Credit Agreement requires the Company to (i) unless certain conditions are met, maintain certain minimum liquidity as specified in the Amended Credit Agreement during the period commencing on March 1, 2021 and ending on June 1, 2021 and (ii) maintain a minimum specified fixed charge coverage ratio on a springing basis if minimum availability requirements as specified in the Amended Credit Agreement are not maintained. The Amended Credit Agreement contains certain customary events of default. If any event of default occurs and is continuing, the Lenders would be entitled to take various actions, including the acceleration of amounts due under the Amended Credit Agreement, and exercise other rights and remedies. Convertible Senior Notes due 2021 In May 2016, the Company issued $75.0 million aggregate principal amount of Convertible Senior Notes, and an additional $11.3 million principal amount to cover over-allotments (Convertible Senior Notes due 2021). The Indenture for the Convertible Notes dated May 31, 2016, which was filed with the Securities and Exchange Commission as an exhibit to a Form 8-K filed on May 31, 2016, contains a complete description of the terms of the Convertible Senior Notes due 2021. The key terms are as follows: Maturity Date: June 1, 2021 unless repurchased or converted earlier Interest Rate: 6.0% cash interest per year Interest Payments Dates: June 1 and December 1 of each year, beginning on December 1, 2016 Initial Conversion Price: $12.58 per common share of the Company Initial Conversion Rate: 79.5165 common shares per $1,000 principal amount of Notes The net proceeds to the Company from the offering were $83.2 million, after deducting the initial underwriters’ discount and fees and the offering expenses payable by the Company. The Company used the net proceeds to repay a portion of the amounts outstanding under its revolving credit agreement. The initial value of the principal amount recorded as a liability at the date of issuance was $66.9 million, using an effective interest rate of 12.0%. The remaining $19.4 million of principal amount was allocated to the conversion feature and recorded as a component of shareholders’ equity at the date of issuance. This amount represents a discount to the debt to be amortized through interest expense using the effective interest method through the maturity of the Convertible Senior Notes due 2021. Transaction costs were allocated to the liability and equity components based on their relative values. Transaction costs attributable to the liability component of $2.4 million are amortized to interest expense over the term of the Convertible Senior Notes due 2021, and transaction costs attributable to the equity component of $0.7 million are included in shareholders’ equity. Convertible Notes Exchange In December 2020, TimkenSteel entered into separate, privately negotiated exchange agreements with a limited number of holders of the Company’s currently outstanding Convertible Senior Notes due 2021. Pursuant to the exchange agreements, the Company exchanged $46.0 million aggregate principal amount of Convertible Senior Notes due 2021 for $46.0 million aggregate principal amount of its new 6.0% Convertible Senior Notes due 2025 (Convertible Senior Notes due 2025 and, together with the Convertible Senior Notes due 2021, the Convertible Notes). The Company did not receive any cash proceeds from the issuance of the Convertible Senior Notes due 2025. The Company evaluated this exchange and determined that $46.0 million of the Convertible Senior Notes due 2021 were deemed to be extinguished, as the present value of the cash flows under the terms of the Convertible Senior Notes due 2025 is at least 10 percent different from the present value of the remaining cash flows under the terms of the Convertible Senior Notes due 2021, as defined by the relevant accounting standards. Pursuant to applicable accounting guidance, the fair value of the extinguished portion of Convertible Senior Notes due 2021 was calculated using a market rate of 9.0%, based on comparable debt instruments, and a remaining term of five and a half months Net carrying amount of extinguished Convertible Senior Notes due 2021 as of December 15, 2020 Principal $ 46.0 Less: Debt issuance costs, net of amortization (0.1 ) Less: Debt discount, net of amortization (1.5 ) Fair value of extinguished Convertible Senior Notes due 2021 as of December 15, 2020 45.3 Loss on extinguishment of debt $ (0.9 ) The amount allocated to the reacquisition of the equity component, included as a reduction to additional paid-in capital on the Consolidated Balance Sheets, was calculated as follows: Fair value of extinguished Convertible Senior Notes due 2021 as of December 15, 2020 $ 45.3 Principal of extinguished Convertible Senior Notes due 2021 46.0 Reduction of additional paid-in capital $ (0.7 ) The remaining accrued and unpaid interest on the $46.0 million of the extinguished Convertible Senior Notes due 2021 was paid in the amount of $0.1 million to the holders on December 15, 2020. The components of the Convertible Senior Notes due 2021 as of December 31, 2020 and December 31, 2019 were as follows: Year Ended December 31, 2020 2019 Principal $ 40.2 $ 86.3 Less: Debt issuance costs, net of amortization (0.1 ) (0.7 ) Less: Debt discount, net of amortization (1.2 ) (7.0 ) Convertible Senior Notes due 2021, net $ 38.9 $ 78.6 The Convertible Senior Notes due 2021 mature on June 1, 2021, and accordingly are classified as a current liability in the consolidated balance sheet as of December 31, 2020. Convertible Senior Notes due 2025 The Convertible Senior Notes due 2025 were issued pursuant to the provisions of the indenture dated May 31, 2016, as supplemented by a supplemental indenture dated December 15, 2020, which was filed with the Securities and Exchange Commission as an exhibit to a Form 8-K on December 15, 2020. The indentures contain a complete description of the terms of the Convertible Senior Notes due 2025. The key terms are as follows: Maturity Date: December 1, 2025 unless repurchased or converted earlier Interest Rate: 6.0% cash interest per year Interest Payments Dates: June 1 and December 1 of each year, beginning on December 1, 2021 Initial Conversion Price: $7.82 per common share of the Company Initial Conversion Rate: 127.8119 common shares per $ 1,000 principal amount of Notes The initial value of the principal amount recorded as a liability at the date of issuance was $40.6 million, using an effective interest rate of 9.0%. The remaining $5.5 million of principal amount was allocated to the conversion feature and recorded as a component of shareholders’ equity at the date of issuance. This amount represents a discount to the debt to be amortized through interest expense using the effective interest method through the maturity of the Convertible Senior Notes due 2025. Transaction costs were allocated to the liability and equity components based on their relative values. Transaction costs attributable to the liability component of $1.3 million are amortized through interest expense over the term of the Convertible Senior Notes due 2025, and transaction costs attributable to the equity component of $0.2 million are included in shareholders’ equity. The components of the Convertible Senior Notes due 2025 as of December 31, 2020 is as follows: Year Ended December 31, 2020 Principal $ 46.0 Less: Debt issuance costs, net of amortization (1.3 ) Less: Debt discount, net of amortization (5.4 ) Convertible Senior Notes due 2025, net $ 39.3 Fair Value Measurement The fair value of the Convertible Senior Notes due 2021 was approximately $34.6 million as of December 31, 2020. The fair value of the Convertible Senior Notes due 2021, which falls within Level 1 of the fair value hierarchy as defined by applicable accounting guidance, is based on the last price traded in December 2020. The fair value of the Convertible Senior Notes due 2025 was approximately $39.3 million as of December 31, 2020. The fair value of the Convertible Senior Notes due 2025, which falls within Level 2 of the fair value hierarchy as defined by applicable accounting guidance, is based on market rates of comparable debt instruments without a conversion option. TimkenSteel’s Credit Facility is variable-rate debt. As such, any outstanding carrying value is a reasonable estimate of fair value as interest rates on these borrowings approximate current market rates. This valuation falls within Level 2 of the fair value hierarchy and is based on quoted prices for similar assets and liabilities in active markets that are observable either directly or indirectly. There were no outstanding borrowings on the Credit Facility as of December 31, 2020. Convertible Notes Interest Expense The following table sets forth total interest expense recognized related to the Convertible Notes: Year Ended December 31, 2020 2019 Contractual interest expense $ 5.2 $ 5.2 Amortization of debt issuance costs 0.5 0.4 Amortization of debt discount 4.4 4.0 Total $ 10.1 $ 9.6 Cash Interest Paid The total cash interest paid for the year ended December 31, 2020 and 2019 was $7.6 million and $11.5 million, respectively. New Accounting Standard related to the Convertible Notes In August 2020, the FASB issued ASU 2020-06, “Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging - Contracts in Entity’s Own Equity (Subtopic 815-40)”, which simplifies the accounting for convertible debt and other equity-linked instruments. The Company has elected to early adopt this standard as of January 1, 2021 using the modified retrospective method of transition. Upon adoption, all outstanding Convertible Notes will be fully classified as a liability, and there will no longer be a separate equity component. We expect this impact will result in a decrease of approximately $10.6 million to additional paid-in capital and an increase of approximately $1.1 million and $5.3 million to current convertible notes, net and non-current convertible notes, net, respectively, on the Consolidated Balance Sheets. Additionally, retained earnings will be adjusted to remove amortization expense recognized in prior periods related to the debt discount and the Convertible Notes will no longer have a debt discount that will be amortized. The impact to retained deficit on the Consolidated Balance Sheets as of January 1, 2021 is a decrease of approximately $4.3 million. We do not expect the new standard to affect the Company’s earnings per share, cash flows and liquidity.

Retirement and Postretirement P

Retirement and Postretirement Plans	12 Months Ended
	Dec. 31, 2020
Defined Benefit Plans And Other Postretirement Benefit Plans Disclosures [Abstract]
Retirement and Postretirement Plans	Note Eligible TimkenSteel employees, including certain employees in foreign countries, participate in the following TimkenSteel-sponsored plans: TimkenSteel Corporation Retirement Plan (Salaried Plan); TimkenSteel Corporation Bargaining Unit Pension Plan, Supplemental Pension Plan of TimkenSteel Corporation, TimkenSteel U.K. Pension Scheme, TimkenSteel Corporation Bargaining Unit Welfare Benefit Plan for Retirees, and TimkenSteel Corporation Welfare Benefit Plan for Retirees. During the second quarter of 2019, the Company amended the TimkenSteel Corporation Bargaining Unit Welfare Plan for Retirees relating to moving Medicare-eligible retirees to an individual plan on a Medicare healthcare exchange. The amendment reduced the postretirement liability by $70.2 million and required the Company to perform a full remeasurement of its obligation and plan assets as of April 30, 2019. The $70.2 million reduction in the APBO was recognized in Other Comprehensive Income (Loss) in 2019 and is being amortized as an offset to postretirement benefit cost over a period of 12 years (average remaining service period). In addition to the reduction of the APBO, the Company recognized a net remeasurement loss of $4.4 million for the year ended December 31, 2019. During the fourth quarter of 2019, the Company amended the Supplemental Pension Plan of TimkenSteel Corporation, which provides for the payment of nonqualified supplemental pension benefits to certain salaried participants in the TimkenSteel Corporation Retirement Plan. The amendment provides for the cessation of benefit accruals under the Supplemental Plan, effective as of December 31, 2020. Effective January 1, 2021, there will be no new accruals of benefits, including with respect to service accruals and the final average compensation determination. Certain of the Company’s named executive officers are participants in the plan. Existing benefits under the plan, as of December 31, 2020, will otherwise continue in accordance with the terms of the plan. This amendment reduced the pension liability, resulting in a curtailment gain of $0.8 million for the year ended December 31, 2019. This curtailment gain was recognized in Other Income (Expense) in the Consolidated Statement of Operations. During the fourth quarter of 2019, the Company amended the TimkenSteel Corporation Retirement Plan, which provides payments of tax-qualified pension benefits to certain salaried employees of the Company and its subsidiaries, to cease benefit accruals under the Pension Plan for all remaining active participants, effective as of December 31, 2020. This plan amendment reduced the pension liability, resulting in a curtailment gain of $8.1 million for the year ended December 31, 2019. This curtailment gain was recognized in Other Income (Expense) in the Consolidated Statement of Operations. During the fourth quarter of 2019, the Company also amended the TimkenSteel Corporation Welfare Benefit Plan for Retirees, under which certain retired salaried employees of the Company and its subsidiaries are eligible to receive a Company contribution for their medical and prescription drug benefits under the retiree welfare plan. The amendment was to eliminate the retiree medical subsidy, effective as of December 31, 2019, for all remaining active salaried participants who retire after December 31, 2019 (provided, however, that participants who were laid off on or before March 31, 2020 and who otherwise qualified for the retiree medical subsidy under the terms of the retiree welfare plan remained entitled to receive the retiree medical subsidy). This plan amendment reduced the postretirement liability by $2.3 million in 2019, was recognized in Other Comprehensive Income (Loss) in 2019 and is being amortized as an offset to postretirement benefit cost in future periods. Pension benefits earned are generally based on years of service and compensation during active employment. TimkenSteel’s funding policy is consistent with the funding requirements of applicable laws and regulations. Asset allocations are established in a manner consistent with projected plan liabilities, benefit payments and expected rates of return for the various asset classes. The expected rate of return for the investment portfolio is based on expected rates of return for various asset classes, as well as historical asset class and fund performance. The following tables set forth the change in benefit obligation, change in plan assets, funded status and amounts recognized on the Consolidated Balance Sheets for the defined benefit pension plans as of December 31, 2020 and 2019: Pension Postretirement Change in benefit obligation: 2020 2019 2020 2019 Benefit obligation at the beginning of year $ 1,311.4 $ 1,178.3 $ 126.2 $ 194.7 Service cost 19.4 17.4 1.0 1.1 Interest cost 42.7 48.9 4.2 5.9 Actuarial (gains) losses 114.8 145.7 6.1 11.4 Benefits paid (71.2 ) (72.3 ) (9.2 ) (14.4 ) Plan amendment — (0.7 ) — (72.5 ) Curtailments — (8.9 ) — — Settlements (24.7 ) — — — Foreign currency translation adjustment 2.7 3.0 — — Benefit obligation at the end of year $ 1,395.1 $ 1,311.4 $ 128.3 $ 126.2 Significant actuarial losses related to changes in benefit obligations for 2020 and 2019 primarily resulted from decreases in discount rates. Pension Postretirement Change in plan assets: 2020 2019 2020 2019 Fair value of plan assets at the beginning of year $ 1,155.4 $ 1,054.4 $ 82.3 $ 86.1 Actual return on plan assets 167.0 167.7 7.0 8.9 Company contributions / payments 1.9 2.0 — 1.7 Benefits paid (71.2 ) (72.3 ) (7.1 ) (14.4 ) Settlements (24.7 ) — — — Foreign currency translation adjustment 3.3 3.6 — — Fair value of plan assets at end of year $ 1,231.7 $ 1,155.4 $ 82.2 $ 82.3 Funded status at end of year $ (163.4 ) $ (156.0 ) $ (46.1 ) $ (43.9 ) The Salaried Plan has a provision that permits employees to elect to receive their pension benefits in a lump sum. In the first quarter of 2020, the cumulative cost of all lump sum payments was projected to exceed the sum of the service cost and interest cost components of net periodic pension cost for the Salaried Plan. As a result, the Company completed a full remeasurement of its pension obligations and plan assets associated with the Salaried Plan during each quarter of 2020. For the year ended December 31, 2020, total settlements were $24.7 million. These settlements are included in the tables above and in the net remeasurement losses (gains) as a component of net periodic benefit cost. The cumulative cost of all lump sums did not exceed service cost and interest cost components of net periodic pension cost for the year ended December 31, 2019. For the years ended December 31, 2020 and 2019, the pension plan had administrative expenses of $3.8 million and $3.5 million, respectively. These expenses are included in benefits paid in the tables above. The accumulated benefit obligation at December 31, 2020 exceeded the fair value of plan assets for two of the Company’s pension plans. For these plans, the benefit obligation was $1,081.2 million, the accumulated benefit obligation was $1,063.9 million and the fair value of plan assets was $884.3 million as of December 31, 2020. The total pension accumulated benefit obligation for all plans was $1,377.6 million and $1,294.5 million as of December 31, 2020 and 2019, respectively. Amounts recognized on the balance sheet at December 31, 2020 and 2019 for TimkenSteel’s pension and postretirement benefit plans include: Pension Postretirement 2020 2019 2020 2019 Non-current assets $ 33.5 $ 25.2 $ — $ — Current liabilities (0.6 ) (0.6 ) (1.7 ) (2.4 ) Non-current liabilities (196.3 ) (180.6 ) (44.4 ) (41.5 ) Total $ (163.4 ) $ (156.0 ) $ (46.1 ) $ (43.9 ) Included in accumulated other comprehensive loss at December 31, 2020 and 2019, were the following before-tax amounts that had not been recognized in net periodic benefit cost: Pension Postretirement 2020 2019 2020 2019 Unrecognized prior service (benefit) cost $ 0.2 $ 0.5 $ (61.9 ) $ (67.8 ) The weighted average assumptions used in determining benefit obligation as of December 31, 2020 and 2019 were as follows: Pension Postretirement Assumptions: 2020 2019 2020 2019 Discount rate 2.68 % 3.42 % 2.65 % 3.42 % Future compensation assumption 2.29 % 2.32 % n/a n/a The weighted average assumptions used in determining benefit cost for the years ended December 31, 2020 and 2019 were as follows: Pension Postretirement Assumptions: 2020 2019 2020 2019 Discount rate ( 1) 3.42 % 4.30 % 3.42 % 4.34% / 3.94% Future compensation assumption 2.32 % 2.36 % n/a n/a Expected long-term return on plan assets 5.80 % 6.41 % 4.50 % 5.00 % (1) The discount rate for the postretirement plans was adjusted after the second quarter 2019 amendment. To calculate benefit costs, the discount rate of 4.34 was used for January to April 2019 and the discount rate of 3.94 was used for May to December 2019. The discount rate assumption is based on current rates of high-quality long-term corporate bonds over the same period that benefit payments will be required to be made. The expected rate of return on plan assets assumption is based on the weighted-average expected return on the various asset classes in the plans’ portfolios. The asset class return is developed using historical asset return performance as well as current market conditions such as inflation, interest rates and equity market performance. For measurement purposes, TimkenSteel assumed a weighted-average annual rate of increase in the per capita cost (health care cost trend rate) of 5.50% and 5.75% for 2020 and 2019, respectively. The components of net periodic benefit cost (income) for the years ended December 31, 2020, 2019 and 2018 were as follows: Pension Postretirement Years Ended December 31, Years Ended December 31, Components of net periodic benefit cost (income): 2020 2019 2018 2020 2019 2018 Service cost $ 19.4 $ 17.4 $ 17.2 $ 1.0 $ 1.1 $ 1.6 Interest cost 42.7 48.9 45.6 4.2 5.9 7.6 Expected return on plan assets (64.3 ) (65.0 ) (74.0 ) (3.5 ) (3.9 ) (4.8 ) Amortization of prior service cost 0.3 0.4 0.5 (6.0 ) (3.8 ) 0.2 Curtailment — (8.9 ) — — — — Net remeasurement losses (gains) 12.1 43.1 49.1 2.6 6.4 (5.6 ) Net Periodic Benefit Cost (Income) $ 10.2 $ 35.9 $ 38.4 $ (1.7 ) $ 5.7 $ (1.0 ) TimkenSteel recognizes its overall responsibility to ensure that the assets of its various defined benefit pension plans are managed effectively and prudently and in compliance with its policy guidelines and all applicable laws. Preservation of capital is important; however, TimkenSteel also recognizes that appropriate levels of risk are necessary to allow its investment managers to achieve satisfactory long-term results consistent with the objectives and the fiduciary character of the pension funds. Asset allocations are established in a manner consistent with projected plan liabilities, benefit payments and expected rates of return for various asset classes. The expected rate of return for the investment portfolios is based on expected rates of return for various asset classes, as well as historical asset class and fund performance. The target allocations for plan assets are 21% equity securities, 61% debt securities and 18% in all other types of investments. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). The inputs used to measure fair value are classified into the following hierarchy: Level 1 - Unadjusted quoted prices in active markets for identical assets or liabilities. Level 2 - Unadjusted quoted prices in active markets for similar assets or liabilities, or unadjusted quoted prices for identical or similar assets or liabilities in markets that are not active, or inputs other than quoted prices that are observable for the asset or liability. Level 3 - Unobservable inputs for the asset or liability. The following table presents the fair value hierarchy for those investments of TimkenSteel’s pension assets measured at fair value on a recurring basis as of December 31, 2020: Total Level 1 Level 2 Level 3 Assets: Cash and cash equivalents $ 9.2 $ 0.9 $ 8.3 $ — U.S government and agency securities 345.7 337.4 8.3 — Corporate bonds 276.9 — 276.9 — Equity securities 68.5 68.5 — — Mutual fund - fixed income 0.1 0.1 — — Mutual fund - equities 22.0 22.0 — — Other 0.2 — 0.2 — Total Assets in the fair value hierarchy $ 722.6 $ 428.9 $ 293.7 $ — Assets measured at net asset value (1) 509.1 — — — Total Assets $ 1,231.7 $ 428.9 $ 293.7 $ — (1) Certain assets that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. Such assets include common collective trusts that invest in equity securities and fixed income securities, limited partnerships, real estate partnerships, hedge funds, and risk parity investments. As of December 31, 2020, these assets are redeemable at net asset value within 90 days. The following table presents the fair value hierarchy for those investments of TimkenSteel’s pension assets measured at fair value on a recurring basis as of December 31, 2019: Total Level 1 Level 2 Level 3 Assets: Cash and cash equivalents $ 12.2 $ 0.9 $ 11.3 $ — U.S government and agency securities 250.3 246.1 4.2 — Corporate bonds 102.7 — 102.7 — Equity securities 49.8 49.8 — — Mutual fund - fixed income 56.4 56.4 — — Total Assets in the fair value hierarchy $ 471.4 $ 353.2 $ 118.2 $ — Assets measured at net asset value (1) 684.0 — — — Total Assets $ 1,155.4 $ 353.2 $ 118.2 $ — (1) Certain assets that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. Such assets include common collective trusts that invest in equity securities and fixed income securities, limited partnerships, real estate partnerships, and risk parity investments. As of December 31, 2019, these assets were redeemable at net asset value within 90 days. The following table presents the fair value hierarchy for those investments of TimkenSteel’s postretirement assets measured at fair value on a recurring basis as of December 31, 2020: Total Level 1 Level 2 Level 3 Assets: Cash and cash equivalents $ 3.0 $ 3.0 $ — $ — Mutual fund - fixed income 11.7 11.7 — — Mutual fund - equities 5.0 5.0 — — Total Assets in the fair value hierarchy $ 19.7 $ 19.7 $ — $ — Assets measured at net asset value (1) 62.5 — — — Total Assets $ 82.2 $ 19.7 $ — $ — (1) Certain assets that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. Such assets include common collective trusts that invest in equity securities and fixed income securities, limited partnerships, real estate partnerships, hedge funds, and risk parity investments. As of December 31, 2020, these assets are redeemable at net asset value within 90 days. The following table presents the fair value hierarchy for those investments of TimkenSteel’s postretirement assets measured at fair value on a recurring basis as of December 31, 2019: Total Level 1 Level 2 Level 3 Assets: Cash and cash equivalents $ 3.0 $ 3.0 $ — $ — Mutual fund - fixed income 15.8 15.8 — — Total Assets in the fair value hierarchy $ 18.8 $ 18.8 $ — $ — Assets measured at net asset value (1) 63.5 — — — Total Assets $ 82.3 $ 18.8 $ — $ — (1) Certain assets that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. Such assets include common collective trusts that invest in equity securities and fixed income securities, limited partnerships, real estate partnerships, and risk parity investments. As of December 31, 2019, these assets were redeemable at net asset value within 90 days. Future benefit payments are expected to be as follows: Benefit Payments: Pension Postretirement 2021 $ 79.1 $ 11.1 2022 86.2 10.3 2023 81.6 9.5 2024 74.5 8.8 2025 74.3 8.4 2026-2030 366.0 37.9 The Company expects to make required contributions to its U.K. pension plan in 2021 of approximately $1.4 million. Defined Contribution Plans The Company recorded expense primarily related to employer matching and non-discretionary contributions to these defined contribution plans of $3.2 million in 2020, $7.1 million in 2019, and $6.3 million in 2018. Effective June 1, 2020, the Company suspended employer matching contributions for all salaried employees. In December 2020, the Company announced that employer matching contributions would be reinstated effective March 1, 2021.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	Note Description of the Plan On April 28, 2016, shareholders of TimkenSteel approved the TimkenSteel Corporation Amended and Restated 2014 Equity and Incentive Compensation Plan (TimkenSteel 2014 Plan), which authorized the Compensation Committee of the TimkenSteel Board of Directors to grant non-qualified or incentive stock options, stock appreciation rights, stock awards (including restricted shares, restricted share unit awards, performance shares, performance units, deferred shares and common shares) and cash awards to TimkenSteel employees and non-employee directors. No more than 11.05 million TimkenSteel common shares may be delivered under the TimkenSteel 2014 Plan (including up to 3.0 million common shares for “replacement awards” to current holders of The Timken Company equity awards under The Timken Company’s equity compensation plans at the time of the spinoff). The TimkenSteel 2014 Plan contains fungible share counting mechanics, which generally means that awards other than stock options and stock appreciation rights will be counted against the aggregate share limit as 2.50 common shares for every one common share that is actually issued or transferred under such awards. With the approval of the TimkenSteel Corporation 2020 Equity and Incentive Compensation Plan, as discussed below, no additional grants may be made under the TimkenSteel 2014 Plan. On May 6, 2020, shareholders of TimkenSteel approved the TimkenSteel Corporation 2020 Equity and Incentive Compensation Plan (TimkenSteel 2020 Plan), which replaced the previously approved TimkenSteel 2014 Plan. The TimkenSteel 2020 Plan authorizes the Compensation Committee to provide cash awards and equity-based compensation in the form of stock options, stock appreciation rights, restricted shares, restricted share units, performance shares, performance units, dividend equivalents, and certain other awards for the primary purpose of providing our employees, officers and directors incentives and rewards for service and/or performance. Subject to adjustment as described in the TimkenSteel 2020 Plan, and subject to the TimkenSteel 2020 Plan share counting rules, a total of 2.0 million common shares of the Company are available for awards granted under the TimkenSteel 2020 Plan (plus shares subject to awards granted under the TimkenSteel 2020 Plan or the TimkenSteel 2014 Plan that are canceled or forfeited, expire, are settled for cash, or are unearned to the extent of such cancellation, forfeiture, expiration, cash settlement or unearned amount, as further described in the TimkenSteel 2020 Plan). These shares may be shares of original issuance or treasury shares, or a combination of both. The aggregate number of shares available under the TimkenSteel 2020 Plan will generally be reduced by one common share for every one share subject to an award granted under the TimkenSteel 2020 Plan. The TimkenSteel 2020 Plan also provides that, subject to adjustment as described in the TimkenSteel 2020 Plan: (1) the aggregate number of common shares actually issued or transferred upon the exercise of incentive stock options will not exceed 2.0 million common shares; and (2) no non-employee director of the Company will be granted, in any period of one calendar year, compensation for such service having an aggregate maximum value (measured at the grant date as applicable, and calculating the value of any awards based on the grant date fair value for financial reporting purposes) in excess of $0.5 million. As of December 31, 2020, approximately 2.2 million shares of TimkenSteel common stock remained available for grants under the TimkenSteel 2020 Plan. Stock Options The following table provides the significant assumptions used to calculate the grant date fair values of stock options granted using a Black-Scholes option pricing method: 2020 2019 2018 Weighted-average fair value per option $ 2.23 $ 5.54 $ 7.46 Risk-free interest rate 0.96 % 2.63 % 2.77 % Dividend yield — % — % — % Expected stock volatility 42.67 % 41.36 % 41.67 % Expected life - years 6 6 6 The risk-free rate for periods within the expected life of the option is based on the U.S. Treasury yield curve in effect at the time of the grant. The following summarizes TimkenSteel stock option activity from January 1, 2020 to December 31, 2020: Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (millions) Outstanding as of December 31, 2019 2,641,570 $ 20.64 Granted 511,020 $ 5.26 Exercised — $ — Canceled, forfeited or expired (221,525 ) $ 12.08 Outstanding as of December 31, 2020 2,931,065 $ 18.61 5.2 $ — Options expected to vest 641,392 $ 8.21 8.7 $ — Options exercisable 2,289,673 $ 21.52 4.2 $ — Stock options presented in the table above represent TimkenSteel awards only, including those held by The Timken Company employees. There were no stock options that were exercised during 2020. Time-Based Restricted Stock Units Time-based restricted stock units are issued with the fair value equal to the closing market price of TimkenSteel common shares on the date of grant. These restricted stock units do not have any performance conditions for vesting. Expense is recognized over the service period, adjusted for any forfeitures that should occur during the vesting period. The following summarizes TimkenSteel stock-settled, time-based restricted stock unit activity from January 1, 2020 to December 31, 2020: Number of Shares Weighted Average Grant Date Fair Value Outstanding as of December 31, 2019 1,103,487 $ 11.89 Granted 931,244 $ 4.24 Vested (548,301 ) $ 10.55 Canceled, forfeited or expired (114,104 ) $ 7.23 Outstanding as of December 31, 2020 1,372,326 $ 7.62 Time-based restricted stock units presented in the table above represent TimkenSteel awards only. Performance-Based Restricted Stock Units Performance-based restricted stock units issued in 2020 are earned based on the average payout (determined under a Compensation Committee approved matrix) for the Company’s relative total shareholder return as compared to an identified peer group of steel companies. The overall vesting period is generally three years, with relative total shareholder return measured for the one, two and three-year periods creating effectively a “nested” 1-year, 2-year, and 3-year plan to support rapid and sustained shareholder value creation. Relative total shareholder return is calculated for each nested performance period by taking the beginning and ending price points based off a 20-trading day average closing stock price as of December 31. The following summarizes TimkenSteel stock-settled performance-based restricted stock unit activity from January 1, 2020 to December 31, 2020: Number of Shares Weighted Average Grant Date Fair Value Outstanding as of December 31, 2019 — $ — Granted 182,180 $ 4.98 Canceled, forfeited or expired (6,216 ) $ 4.97 Outstanding as of December 31, 2020 175,964 $ 4.98 The table above does not include the stock-settled performance units that were granted before 2020 as these grants are not expected to payout. Other Information TimkenSteel recognized stock-based compensation expense of $6.6 million, $7.4 million and $7.3 million for the years ended December 31, 2020, 2019 and 2018, respectively. As of December 31, 2020, future stock-based compensation expense related to the unvested portion of all awards is approximately $6.1 million, which is expected to be recognized over a weighted average period of 1.5 years. Certain restricted stock units, including some performance-based restricted stock units, are settled in cash and were adjusted and substituted. TimkenSteel has a liability of $0.1 million as of December 31, 2020 and 2019 for these awards which was included in salaries, wages and benefits, and other non-current liabilities on the Consolidated Balance Sheets. There were no cash-settled restricted stock units granted during 2020 or 2019. On December 16, 2020, the Board of Directors of TimkenSteel appointed and elected Michael S. Williams as President and Chief Executive Officer of the Company, effective January 1, 2021. The Board further appointed and elected Mr. Williams as a director, also effective January 1, 2021. The Compensation Committee of TimkenSteel’s Board of Directors approved grants of inducement equity awards to Mr. Williams consisting of time-based restricted share units covering 423,400 TimkenSteel’s common shares, with a grant date fair value of $5.17 and performance-based restricted share units covering a target number of 423,400 of TimkenSteel’s common shares (with a maximum payout opportunity of 635,100 common shares), with a grant date fair value of $5.68. The design of the performance-based restricted share units are similar to the performance-vested restricted stock units discussed above. These awards were granted outside of the TimkenSteel Corporation 2020 Equity and Incentive Compensation Plan as inducements material to Mr. Williams' acceptance of employment with TimkenSteel. The grant date for the awards is January 5, 2021 with future stock-based compensation expense of $4.6 million, which is expected to be recognized over three years.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2020
Accumulated Other Comprehensive Income Loss Net Of Tax [Abstract]
Accumulated Other Comprehensive Income (Loss)	Note Changes in accumulated other comprehensive income (loss) for the years ended December 31, 2020 and 2019 by component were as follows: Foreign Currency Translation Adjustments Pension and Postretirement Liability Adjustments Total Balance as of December 31, 2019 $ (6.8 ) $ 51.5 $ 44.7 Other comprehensive income before reclassifications, before income tax 1.4 — 1.4 Amounts reclassified from accumulated other comprehensive income (loss), before income tax — (5.6 ) (5.6 ) Tax effect — (0.1 ) (0.1 ) Net current period other comprehensive income, net of income taxes 1.4 (5.7 ) (4.3 ) Balance as of December 31, 2020 $ (5.4 ) $ 45.8 $ 40.4 Foreign Currency Translation Adjustments Pension and Postretirement Liability Adjustments Total Balance at December 31, 2018 $ (7.3 ) $ (1.6 ) $ (8.9 ) Other comprehensive income before reclassifications, before income tax 0.5 — 0.5 Amounts reclassified from accumulated other comprehensive income (loss), before income tax — (2.4 ) (2.4 ) Amounts deferred to accumulated other comprehensive income (loss), before income tax — 72.2 72.2 Tax effect — (16.7 ) (16.7 ) Net current period other comprehensive income, net of income taxes 0.5 53.1 53.6 Balance as of December 31, 2019 $ (6.8 ) $ 51.5 $ 44.7 The amount reclassified from accumulated other comprehensive income (loss) in the year ended December 31, 2020 for the pension and postretirement liability adjustment was included in other (income) expense, net in the Consolidated Statements of Operations.

Contingencies

Contingencies	12 Months Ended
	Dec. 31, 2020
Loss Contingency Accrual Disclosures [Abstract]
Contingencies	Note TimkenSteel has a number of loss exposures incurred in the ordinary course of business, such as environmental claims, product warranty claims, and litigation. Establishing loss reserves for these matters requires management’s estimate and judgment regarding risk exposure and ultimate liability or realization. These loss reserves are reviewed periodically and adjustments are made to reflect the most recent facts and circumstances. Accruals related to environmental claims represent management’s best estimate of the fees and costs associated with these claims. Although it is not possible to predict with certainty the outcome of such claims, management believes that their ultimate dispositions should not have a material adverse effect on our financial position, cash flows or results of operations. As of December 31, 2020 and 2019, TimkenSteel had a $1.0 million and $1.5 million

Relationships with The Timken C

Relationships with The Timken Company and Related Entities	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Relationships with The Timken Company and Related Entities	Note Prior to the spinoff on June 30, 2014, TimkenSteel was managed and operated in the normal course of business with other affiliates of The Timken Company. Transactions between The Timken Company and TimkenSteel, with the exception of sale and purchase transactions and reimbursements for payments made to third-party service providers by The Timken Company on TimkenSteel’s behalf, are reflected in equity in the Consolidated Balance Sheets as net parent investment and in the Consolidated Statements of Cash Flows as a financing activity in net transfers (to)/from The Timken Company and affiliates. Transactions with The Timken Company TimkenSteel sold finished goods to The Timken Company. During the years ended December 31, 2020, 2019 and 2018, revenues from related-party sales of products totaled $23.4 million or 2.8% of net sales, $26.1 million or 2.2% of net sales, and $43.2 million or 2.7% of net sales, respectively. TimkenSteel did not purchase material from The Timken Company during the years ending December 31, 2020, 2019 or 2018. In addition, certain TimkenSteel third-party service providers were paid by The Timken Company on behalf of TimkenSteel. TimkenSteel would subsequently reimburse The Timken Company in cash for such payments. Material Agreements Between TimkenSteel and The Timken Company On June 30, 2014, TimkenSteel entered into a separation and distribution agreement and several other agreements with The Timken Company to effect the spinoff and to provide a framework for the relationship with The Timken Company. These agreements govern the relationship between TimkenSteel and The Timken Company subsequent to the completion of the spinoff and provide for the allocation between TimkenSteel and The Timken Company of assets, liabilities and obligations attributable to periods prior to the spinoff. Because these agreements were entered into in the context of a related party transaction, the terms may not be comparable to terms that would be obtained in a transaction between unaffiliated parties. Separation and Distribution Agreement — The separation and distribution agreement contains the key provisions relating to the spinoff, including provisions relating to the principal intercompany transactions required to effect the spinoff, the conditions to the spinoff and provisions governing the relationships between TimkenSteel and The Timken Company after the spinoff. Tax Sharing Agreement — The tax sharing agreement generally governs TimkenSteel’s and The Timken Company’s respective rights, responsibilities and obligations after the spinoff with respect to taxes for any tax period ending on or before the distribution date, as well as tax periods beginning before and ending after the distribution date. Generally, TimkenSteel is liable for all pre-distribution U.S. federal income taxes, foreign income taxes and non-income taxes attributable to TimkenSteel’s business, and all other taxes attributable to TimkenSteel, paid after the distribution. In addition, the tax sharing agreement addresses the allocation of liability for taxes that are incurred as a result of restructuring activities undertaken to effectuate the distribution. The tax sharing agreement also provides that TimkenSteel is liable for taxes incurred by The Timken Company that arise as a result of TimkenSteel’s taking or failing to take, as the case may be, certain actions that result in the distribution failing to meet the requirements of a tax-free distribution under Section 355 of the Internal Revenue Code of 1986, as amended. Employee Matters Agreement — TimkenSteel entered into an employee matters agreement with The Timken Company, which generally provides that TimkenSteel and The Timken Company each has responsibility for its own employees and compensation plans, subject to certain exceptions as described in the agreement. In general, prior to the spinoff, TimkenSteel employees participated in various retirement, health and welfare, and other employee benefit and compensation plans maintained by The Timken Company. Following the spinoff (or earlier, in the case of the tax-qualified defined benefit plans and retiree medical plans), pursuant to the employee matters agreement, TimkenSteel employees and former employees generally participate in similar plans and arrangements established and maintained by TimkenSteel. The employee matters agreement provides for the bifurcation of equity awards as described in Note 16 - Stock-Based Compensation. Among other things, the employee matters agreement also provides for TimkenSteel’s assumption of certain employment-related contracts that its employees originally entered into with The Timken Company, the allocation of certain employee liabilities and the cooperation between TimkenSteel and The Timken Company in the sharing of employee information.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2020
Subsequent Events [Abstract]
Subsequent Events	Note 20 – Subsequent Events On February 16, 2021, management announced a plan to indefinitely idle its Harrison melt and cast assets, late in the first quarter of 2021. Going forward, all of the Company’s melting and casting activities will take place at the Faircrest location. The Company is working collaboratively with employees, suppliers and a number of customers to ensure a well-organized and efficient transition. The Company’s rolling and finishing operations at Harrison will not be impacted by these actions. At this time, the Company is still reviewing Harrison melt and cast related assets to determine potential alternative uses for selected assets. As a result, the Company estimates that it will recognize non-cash charges of between $8 million and $10 million related to the write down of the associated Harrison melt and cast assets in the first quarter of 2021. The Company does not anticipate incurring any required cash expenditures related to these charges. There are approximately 100 Canton-based hourly employees, represented by the United Steelworkers, potentially impacted by this decision. Position eliminations will be processed in accordance with the terms and conditions of the 2017 Basic Labor Agreement between TimkenSteel Corporation and the United Steel, Paper and Forestry, Rubber, Manufacturing, Energy, Allied Industrial and Service Workers International Union, Local 2003. As such, the ultimate number of employees impacted is unknown at this time.

Selected Quarterly Financial Da

Selected Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data (Unaudited)	SUPPLEMENTAL DATA Selected Quarterly Financial Data (Unaudited) (dollars in millions, except per share data) The following is selected quarterly operating results for each quarter of fiscal 2020 and 2019 for TimkenSteel. Quarters ended December 31, 2020 September 30, 2020 June 30, 2020 March 31, 2020 Net sales $ 211.2 $ 205.9 $ 154.0 $ 259.7 Gross profit 14.2 (2.4 ) (4.0 ) 7.8 Net income (loss) (12.8 ) (13.9 ) (15.3 ) (19.9 ) Per share data: Basic earnings (loss) per share $ (0.28 ) $ (0.31 ) $ (0.34 ) $ (0.44 ) Diluted earnings (loss) per share $ (0.28 ) $ (0.31 ) $ (0.34 ) $ (0.44 ) Quarters ended December 31, 2019 September 30. 2019 June 30, 2019 March 31, 2019 Net sales $ 226.9 $ 274.2 $ 336.7 $ 371.0 Gross profit (18.0 ) (2.6 ) 14.8 28.4 Net income (loss) (84.6 ) (17.0 ) (11.9 ) 3.5 Per share data: Basic earnings (loss) per share $ (1.89 ) $ (0.38 ) $ (0.27 ) $ 0.08 Diluted earnings (loss) per share $ (1.89 ) $ (0.38 ) $ (0.27 ) $ 0.08

Schedule II-Valuation and Quali

Schedule II-Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2020
Valuation And Qualifying Accounts [Abstract]
Schedule II-Valuation and Qualifying Accounts	Schedule II-Valuation and Qualifying Accounts Allowance for uncollectible accounts: 2020 2019 2018 Balance at Beginning of Period $ 1.5 $ 1.7 $ 1.4 Additions: Charged to Costs and Expenses (1) — — 0.3 Deductions (2) (0.2 ) (0.2 ) — Balance at End of Period $ 1.3 $ 1.5 $ 1.7 Allowance for inventory reserves 2020 2019 2018 Balance at Beginning of Period $ 10.7 $ 6.1 $ 8.9 Additions: Charged to Costs and Expenses (3) 4.1 9.0 1.6 Deductions (4) (0.9 ) (4.4 ) (4.4 ) Balance at End of Period $ 13.9 $ 10.7 $ 6.1 Valuation allowance on deferred tax assets: 2020 2019 2018 Balance at Beginning of Period $ 34.9 $ 43.7 $ 36.6 Additions: Charged to Costs and Expenses (5) 12.4 — 7.1 Charged to Other Accounts (6) 1.4 16.7 — Deductions (7) (1.0 ) (25.5 ) — Balance at End of Period $ 47.7 $ 34.9 $ 43.7 (1) Provision for uncollectible accounts included in expenses. (2) Actual accounts written off against the allowance, net of recoveries. (3) Provisions for surplus and obsolete inventory and lower cost or net realizable value included in expenses. (4) Inventory items written off against the allowance. (5) Increase in valuation allowance is recorded as a component of the provision for income taxes. (6) Amount relates to valuation allowances recorded against other comprehensive income (loss). (7) Amount primarily relates to an additional paid-in capital adjustment associated with the Convertible Notes for the year ended December 31, 2020 and the change in accounting principle from LIFO to FIFO for the year ended December 31, 2019.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Revenue Recognition	Revenue Recognition: TimkenSteel recognizes revenue from contracts at a point in time when it has satisfied its performance obligation and the customer obtains control of the goods, at the amount that reflects the consideration the Company expects to receive for those goods. The Company receives and acknowledges purchase orders from its customers, which define the quantity, pricing, payment and other applicable terms and conditions. In some cases, the Company receives a blanket purchase order from its customer, which includes pricing, payment and other terms and conditions, with quantities defined at the time the customer issues periodic releases from the blanket purchase order. Certain contracts contain variable consideration, which primarily consists of rebates that are accounted for in net sales and accrued based on the estimated probability of the requirements being met.
Cash Equivalents	Cash Equivalents: TimkenSteel considers all highly liquid investments with a maturity of three months or less when purchased to be cash equivalents.
Accounts Receivables, Net	Accounts Receivables, Net: The Company’s accounts receivables arise from sales to customers across the mobile, industrial, energy, and other end-markets. The allowance for doubtful account reserve has been established using qualitative and quantitative methods. In general, account balances greater than one year of age or sent to third party collection are fully reserved. Account balances for customers that are viewed as higher risk are also analyzed for a reserve. In addition to these methods, the allowance for doubtful accounts is adjusted for forward looking uncollectible balances based on end-market outlook and dynamics, such as in the energy and mobile end-markets in 2020. The amount recorded was based on the Company’s assessment of the risk presented by customers in these end - markets as a result of the COVID-19 pandemic as well as geo-political factors facing the energy end - market. Historically, TimkenSteel’s allowance for doubtful accounts write-offs have been immaterial.
Inventories, Net	Inventories, Net: Inventories are stated at lower of cost or net realizable value. All inventories, including raw materials, manufacturing supplies inventory as well as international (outside the U.S.) inventories, have been valued using the FIFO or average cost method as of December 31, 2020 and 2019.
Property, Plant and Equipment, Net	Property, Plant and Equipment, Net: Property, plant and equipment, net are valued at cost less accumulated depreciation. Maintenance and repairs are charged to expense as incurred. The provision for depreciation is computed principally by the straight-line method based upon the estimated useful lives of the assets. The useful lives are approximately 30 years for buildings and three to 20 years for machinery and equipment.
Intangible Assets, Net	Intangible Assets, Net: Intangible assets subject to amortization are amortized on a straight-line method over their legal or estimated useful lives, with useful lives ranging from 3 to 15 years. In accordance with applicable accounting guidance, TimkenSteel capitalizes certain costs incurred for computer software developed or obtained for internal use. TimkenSteel capitalizes substantially all external costs and qualifying internal costs related to the purchase and implementation of software projects used for business operations. Capitalized software costs primarily include purchased software and external consulting fees. Capitalized software projects are amortized over the estimated useful lives of the software.
Long-lived Assets	Long-lived Assets: Long-lived assets (including tangible assets and intangible assets subject to amortization) are reviewed for impairment when events or changes in circumstances have occurred indicating that the carrying value of the assets may not be recoverable. TimkenSteel tests recoverability of long-lived assets at the lowest level for which there are identifiable cash flows that are independent from the cash flows of other assets. Assets and asset groups held and used are measured for recoverability by comparing the carrying amount of the asset or asset group to the sum of future undiscounted net cash flows expected to be generated by the asset or asset group. Assumptions and estimates about future values and remaining useful lives of TimkenSteel’s long-lived assets are complex and subjective. They can be affected by a variety of factors, including external factors such as industry and economic trends and internal factors such as changes in TimkenSteel’s business strategy and internal forecasts. If an asset or asset group is considered to be impaired, the impairment loss that would be recognized is the amount by which the carrying amount of the assets exceeds the fair value of the assets. To determine fair value, TimkenSteel uses internal cash flow estimates discounted at an appropriate interest rate, third party appraisals, as appropriate, and/or market prices of similar assets, when available. Refer to “Note 6 - Disposition of Non-Core Assets” and “Note 11 - Property, Plant and Equipment” for additional information.
Product Warranties	Product Warranties: TimkenSteel accrues liabilities for warranties based upon specific claim incidents in accordance with accounting rules relating to contingent liabilities. Should TimkenSteel become aware of a specific potential warranty claim for which liability is probable and reasonably estimable, a specific charge is recorded and accounted for accordingly. TimkenSteel had no significant warranty claims for the years ended December 31, 2020, 2019 or 2018.
Income Taxes	Income Taxes: Deferred tax assets and liabilities are recorded for the future tax consequences attributable to differences between financial statement carrying amounts of existing assets and liabilities and their respective tax bases, as well as net operating loss and tax credit carryforwards. TimkenSteel accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined on the basis of the differences between the financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. TimkenSteel recognizes deferred tax assets to the extent TimkenSteel believes these assets are more likely than not to be realized. In making such a determination, TimkenSteel considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. If TimkenSteel determines that it would be able to realize deferred tax assets in the future in excess of their net recorded amount, TimkenSteel would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. TimkenSteel records uncertain tax positions in accordance with applicable accounting guidance , on the basis of a two-step process whereby (1) TimkenSteel determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position, and (2) for those tax positions that meet the more-likely-than-not recognition threshold, TimkenSteel recognizes the largest amount of tax benefit that is more than 50 percent likely to be realized upon ultimate settlement with the related tax authority. TimkenSteel recognizes interest and penalties related to unrecognized tax benefits within the provision (benefit) for income taxes line in the accompanying Consolidated Statements of Operations. Accrued interest and penalties are included within the related tax liability line in the Consolidated Balance Sheets. The Company made the accounting policy election to treat taxes related to Global Intangible Low-Taxed Income (GILTI) as a current period expense when incurred.
Foreign Currency	Foreign Currency: Assets and liabilities of subsidiaries are translated at the rate of exchange in effect on the balance sheet date. Income and expenses are translated at the average rates of exchange prevailing during the year. The related translation adjustments are reflected as a separate component of accumulated other comprehensive loss. Gains and losses resulting from foreign currency transactions are included in other (income) expense, net in the Consolidated Statements of Operations. TimkenSteel realized a foreign currency exchange loss of $0.2
Pension and Other Postretirement Benefits	Pension and Other Postretirement Benefits: TimkenSteel recognizes an overfunded status or underfunded status (e.g., the difference between the fair value of plan assets and the benefit obligations) as either an asset or a liability for its defined benefit pension and other postretirement benefit plans on the Consolidated Balance Sheets. The Company recognizes actuarial gains and losses immediately through net periodic benefit cost in the Consolidated Statements of Operations upon the annual remeasurement at December 31, or on an interim basis as triggering events warrant remeasurement. In addition, the Company uses fair value to account for the value of plan assets.
Stock-Based Compensation	Stock-Based Compensation: TimkenSteel recognizes stock-based compensation expense based on the grant date fair value of the stock-based awards over their required vesting period on a straight-line basis, whether the awards were granted with graded or cliff vesting. Stock options are issued with an exercise price equal to the closing market price of TimkenSteel common shares on the date of grant. The fair value of stock options is determined using a Black-Scholes option pricing model, which incorporates assumptions regarding the expected volatility, the expected option life, the risk-free interest rate and the expected dividend yield. Performance-vested restricted stock units issued in 2020 vest based on achievement of a total shareholder return (TSR) metric. The TSR metric is considered a market condition, which requires TimkenSteel to reflect it in the fair value on grant date using an advanced option-pricing model. The fair value of each performance share was therefore determined using a Monte Carlo valuation model, a generally accepted lattice pricing model. The Monte Carlo valuation model, among other factors, uses commonly-accepted economic theory underlying all valuation models, estimates fair value using simulations of future share prices based on stock price behavior and considers the correlation of peer company returns in determining fair value. The fair value of stock-based awards that will settle in TimkenSteel common shares, other than stock options and performance-vested restricted stock units, is based on the closing market price of TimkenSteel common shares on the grant date. The fair values of stock-based awards that will settle in cash are remeasured at each reporting period until settlement of the awards. TimkenSteel recognizes all excess tax benefits and tax deficiencies as income tax expense or benefit in the Consolidated Statements of Operations. The excess tax benefits and tax deficiencies are considered discrete items in the reporting period they occur and are not included in the estimate of an entity’s annual effective tax rate.
Research and Development	Research and Development: Expenditures for TimkenSteel research and development amounted to $1.8 million for the year ended December 31, 2020, $4.1 million for the year ended December 31, 2019 and $8.1 million for the year ended December 31, 2018, and were recorded as a component of selling, general and administrative expenses in the Consolidated Statements of Operations. These expenditures may fluctuate from year to year depending on special projects and the needs of TimkenSteel and its customers.
Adoption of New Accounting Standards	Adoption of New Accounting Standards The Company adopted the following Accounting Standard Updates (ASU) during the year ended December 31, 2020. The adoption of these standards did not have a material impact on the Consolidated Financial Statements or the related Notes to the Consolidated Financial Statements. Standards Adopted Description Date of Adoption ASU 2016-13, Measurement of Credit Losses on Financial Instruments (Topic 326) The standard changes how entities will measure credit losses for most financial assets, including trade and other receivables, and replaces the current incurred loss approach with an expected loss model. January 1, 2020 ASU 2018-13, Fair Value Measurement (Topic 820) The standard eliminates, modifies and adds disclosure requirements for fair value measurements. January 1, 2020 ASU 2018-14, Compensation - Retirement Benefits - Defined Benefit Plans - General (Subtopic 715-20) The standard eliminates, modifies and adds disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. January 1, 2020 ASU 2018-15, Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40) The standard aligns the requirements for capitalizing implementation costs in cloud computing software arrangements with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. January 1, 2020 ASU 2020-04, Reference Rate Reform (Topic 848) The standard provides optional expedients and exceptions for applying generally accepted accounting principles to contracts, hedging relationships and other transactions affected by reference rate reform if certain criteria are met. March 12, 2020 Accounting Standards Issued But Not Yet Adopted The Company has considered the recent ASUs issued by the Financial Accounting Standards Board summarized below: Standard Pending Adoption Description Effective Date Anticipated Impact ASU 2019-12, Income Taxes (Topic 740) The standard simplifies the accounting for income taxes by removing various exceptions. January 1, 2021 The Company has evaluated the impact of adopting of this ASU and it will not have a material impact on the Consolidated Financial Statements. ASU 2020-06, Debt - Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging - Contracts in Entity’s Own Equity (Subtopic 815-40) The standard simplifies the accounting for convertible instruments, as well as the diluted net income per share calculation. The standard also removes certain settlement conditions that are required for equity contracts to qualify for the derivative scope exception. The amendments in the standard are effective for fiscal years beginning after December 15, 2021, however early adoption is permitted for fiscal years beginning after December 15, 2020. Entities can adopt the guidance through either a modified retrospective method of transition or a fully retrospective method of transition. January 1, 2021 (Early Adoption Date) The Company has elected to early adopt this standard as of January 1, 2021 using the modified retrospective method of transition. We expect this standard will have a material impact on the Consolidated Financial Statements. Refer to “Note 14 – Financing Arrangements” for additional information.

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Revenue from External Customers by Geographic Areas	Year Ended December 31, 2020 2019 2018 Net Sales: United States $ 746.8 $ 1,096.8 $ 1,456.2 Foreign 83.9 112.0 154.4 $ 830.7 $ 1,208.8 $ 1,610.6
Long-lived Assets by Geographic Areas	December 31, 2020 2019 Long-lived Assets, net: United States $ 599.1 $ 654.8 Foreign 1.0 0.2 $ 600.1 $ 655.0

Revenue Recognition (Tables)

Revenue Recognition (Tables)	12 Months Ended
	Dec. 31, 2020
Revenue From Contract With Customer [Abstract]
Disaggregation of Revenue	The following table provides the major sources of revenue by end-market sector for the years ended December 31, 2020, 2019 and 2018: Year Ended December 31, 2020 2019 2018 Mobile $ 346.0 $ 479.3 $ 553.9 Industrial 391.7 486.3 637.5 Energy 53.2 166.4 265.6 Other ( 1) 39.8 76.8 153.6 Total Net Sales $ 830.7 $ 1,208.8 $ 1,610.6 (1) “Other” for sales by end-market sector includes the Company’s scrap and OCTG billet sales. The following table provides the major sources of revenue by product type for the years ended December 31, 2020, 2019 and 2018: Year Ended December 31, 2020 2019 2018 Bar $ 502.5 $ 783.0 $ 1,030.7 Tube 101.4 151.8 254.7 Value-add 208.1 240.6 284.3 Other ( 2) 18.7 33.4 40.9 Total Net Sales $ 830.7 $ 1,208.8 $ 1,610.6 (2) “Other” for sales by product type includes the Company’s scrap sales.

Restructuring Charges (Tables)

Restructuring Charges (Tables)	12 Months Ended
	Dec. 31, 2020
Restructuring And Related Activities [Abstract]
Schedule of Restructuring Reserve	The following is a summary of the restructuring reserve for the twelve months ended December 31, 2020 and 2019: Balance at December 31, 2019 $ 6.0 Expenses (1) 3.1 Payments (7.6 ) Balance at December 31, 2020 $ 1.5 (1) Expenses of $3.1 million exclude stock compensation of $0.1 million that was accelerated as a result of the Company’s restructuring activities. Balance at December 31, 2018 $ — Expenses (2) 8.6 Payments (2.6 ) Balance at December 31, 2019 $ 6.0 (2) Expenses of $8.6 million exclude stock compensation of $0.3 million that was accelerated as a result of the Company’s restructuring activities.

Other (Income) Expense, Net (Ta

Other (Income) Expense, Net (Tables)	12 Months Ended
	Dec. 31, 2020
Other Income And Expenses [Abstract]
Schedule of Other (Income) Expense, Net	The following table provides the components of other (income) expense, net for the years ended December 31, 2020, 2019 and 2018: Year Ended December 31, 2020 2019 2018 Pension and postretirement non-service benefit (income) loss $ (26.6 ) $ (17.5 ) $ (25.2 ) Loss (gain) from remeasurement of benefit plans 14.7 40.6 43.5 Foreign currency exchange loss (gain) 0.2 — 0.2 Employee retention credit (2.3 ) — — Miscellaneous (income) expense (0.2 ) 0.2 0.1 Total other (income) expense, net $ (14.2 ) $ 23.3 $ 18.6

Income Tax Provision (Tables)

Income Tax Provision (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Schedule of Income before Income Tax, Domestic and Foreign	Income (loss) from operations before income taxes, based on geographic location of the operations to which such earnings are attributable, is provided below. Years Ended December 31, 2020 2019 2018 United States $ (64.1 ) $ (130.8 ) $ (10.1 ) Non-United States 3.4 4.7 1.9 Loss from operations before income taxes $ (60.7 ) $ (126.1 ) $ (8.2 )
Schedule of (Benefit) Provision for Income Taxes	The provision (benefit) for income taxes consisted of the following: Years Ended December 31, 2020 2019 2018 Current: Federal $ 0.6 $ — $ — State and local — 0.1 0.3 Foreign 0.5 0.4 0.7 Total current tax expense (benefit) $ 1.1 $ 0.5 $ 1.0 Deferred: Federal $ (0.4 ) $ (14.4 ) $ 0.4 State and local 0.5 (2.0 ) — Foreign — (0.2 ) 0.4 Total deferred tax expense (benefit) 0.1 (16.6 ) 0.8 Provision (benefit) for incomes taxes $ 1.2 $ (16.1 ) $ 1.8
Schedule of Effective Income Tax Rate Reconciliation	The reconciliation between TimkenSteel’s effective tax rate on income (loss) from continuing operations and the statutory tax rate is as follows: Years Ended December 31, 2020 2019 2018 U.S. federal income tax provision (benefit) at statutory rate $ (12.7 ) $ (26.5 ) $ (6.3 ) Adjustments: State and local income taxes, net of federal tax benefit 2.3 (1.3 ) (0.5 ) Foreign earnings taxed at different rates 0.1 — 0.2 U.S. research tax credit — 0.2 (0.2 ) Valuation allowance 10.3 10.2 7.5 Global intangible low-taxed income — 0.2 0.5 Permanent differences 1.3 1.3 0.8 Other items, net (0.1 ) (0.2 ) (0.2 ) Provision (benefit) for income taxes $ 1.2 $ (16.1 ) $ 1.8 Effective tax rate (2.0 )% 12.8 % (5.9 )%
Schedule of Deferred Tax Assets and Liabilities	The effect of temporary differences giving rise to deferred tax assets and liabilities at December 31, 2020 and 2019 was as follows: December 31, 2020 2019 Deferred tax liabilities: Depreciation $ (97.5 ) $ (98.6 ) Inventory (16.2 ) (24.3 ) Convertible debt (1.6 ) (1.7 ) Leases - right-of-use asset (5.0 ) (3.4 ) Other, net (0.3 ) (0.7 ) Deferred tax liabilities $ (120.6 ) $ (128.7 ) Deferred tax assets: Pension and postretirement benefits $ 50.3 $ 47.9 Other employee benefit accruals 8.7 7.2 Tax loss carryforwards 94.4 86.0 Intangible assets 1.0 1.1 Inventory 4.5 5.4 State decoupling 2.8 4.5 Lease liability 5.0 3.4 Interest limitation — 6.0 Other, net 0.6 1.2 Deferred tax assets subtotal $ 167.3 $ 162.7 Valuation allowances (47.7 ) (34.9 ) Deferred tax assets 119.6 127.8 Net deferred tax assets (liabilities) $ (1.0 ) $ (0.9 )

Earnings (Loss) Per Share (Tabl

Earnings (Loss) Per Share (Tables)	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table sets forth the reconciliation of the numerator and the denominator of basic and diluted loss per share for the years ended December 31, 2020, 2019 and 2018: Year Ended December 31, 2020 2019 2018 Numerator: Net income (loss) $ (61.9 ) $ (110.0 ) $ (10.0 ) Denominator: Weighted average shares outstanding, basic 45.0 44.8 44.6 Weighted average shares outstanding, diluted 45.0 44.8 44.6 Basic earnings (loss) per share $ (1.38 ) $ (2.46 ) $ (0.22 ) Diluted earnings (loss) per share $ (1.38 ) $ (2.46 ) $ (0.22 )

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2020
Inventory Disclosure [Abstract]
Schedule of Components of Inventory	The components of inventories as of December 31, 2020 and 2019 were as follows: December 31, 2020 2019 Manufacturing supplies $ 37.6 $ 49.8 Raw materials 20.0 26.0 Work in process 79.1 123.7 Finished products 55.6 93.1 Gross inventory 192.3 292.6 Allowance for inventory reserves (13.9 ) (10.7 ) Total inventories, net $ 178.4 $ 281.9

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	12 Months Ended
	Dec. 31, 2020
Property Plant And Equipment [Abstract]
Schedule of Property, Plant and Equipment	The components of property, plant and equipment, net as of December 31, 2020 and 2019 were as follows: December 31, 2020 2019 Land $ 13.3 $ 13.3 Buildings and improvements 422.5 419.0 Machinery and equipment 1,398.7 1,404.6 Construction in progress 11.0 30.9 Subtotal 1,845.5 1,867.8 Less allowances for depreciation (1,275.7 ) (1,241.4 ) Property, plant and equipment, net $ 569.8 $ 626.4

Intangible Assets (Tables)

Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2020
Goodwill And Intangible Assets Disclosure [Abstract]
Schedule of Finite-Lived Intangible Assets	The components of intangible assets, net as of December 31, 2020 and 2019 were as follows: December 31, 2020 December 31, 2019 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Customer relationships $ 6.3 $ 5.4 $ 0.9 $ 6.3 $ 5.0 $ 1.3 Technology use 9.0 9.0 — 9.0 8.0 1.0 Capitalized software 58.0 49.6 8.4 61.1 49.1 12.0 Total intangible assets $ 73.3 $ 64.0 $ 9.3 $ 76.4 $ 62.1 $ 14.3
Schedule of Estimated Annual Amortization Expense	Based upon the intangible assets subject to amortization as of December 31, 2020, TimkenSteel’s estimated annual amortization for the five succeeding years is shown below (in millions): Year Amortization Expense 2021 $ 3.1 2022 2.6 2023 2.0 2024 1.0 2025 0.1

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Lease, Cost	The Company recorded lease cost for the year ended December 31, 2020 as follows: Year Ended December 31, 2020 2019 Operating lease cost $ 8.8 $ 7.4 Short-term lease cost 0.7 1.9 Total lease cost $ 9.5 $ 9.3 Supplemental cash flow information related to leases was as follows: Year Ended December 31, 2020 2019 Cash paid for amounts included in the measurement of operating lease liabilities $ 8.8 $ 7.5 Right-of-use assets obtained in exchange for operating lease obligations $ 12.5 $ 4.3
Future Lease Maturity	Future minimum lease payments under non-cancellable leases as of December 31, 2020 were as follows: 2021 $ 8.4 2022 5.7 2023 4.8 2024 2.7 After 2024 0.9 Total future minimum lease payments 22.5 Less amount of lease payment representing interest (1.5 ) Total present value of lease payments $ 21.0

Financing Arrangements (Tables)

Financing Arrangements (Tables)	12 Months Ended
	Dec. 31, 2020
Debt Instrument [Line Items]
Summary of Current and Non-current Debt	The following table summarizes the current and non-current debt as of December 31, 2020 and 2019: Year Ended December 31, 2020 2019 Credit Agreement $ — $ 90.0 Convertible Senior Notes due 2021 38.9 78.6 Convertible Senior Notes due 2025 39.3 0.0 Total debt $ 78.2 $ 168.6 Less current portion of debt 38.9 — Total non-current portion of debt $ 39.3 $ 168.6
Schedule of Net Carrying Amount of Extinguished Convertible Senior Notes	Net carrying amount of extinguished Convertible Senior Notes due 2021 as of December 15, 2020 Principal $ 46.0 Less: Debt issuance costs, net of amortization (0.1 ) Less: Debt discount, net of amortization (1.5 ) Fair value of extinguished Convertible Senior Notes due 2021 as of December 15, 2020 45.3 Loss on extinguishment of debt $ (0.9 )
Schedule of Amount Allocated to Reacquisition of Equity Component Included as Reduction To Additional Paid-In Capital	The amount allocated to the reacquisition of the equity component, included as a reduction to additional paid-in capital on the Consolidated Balance Sheets, was calculated as follows: Fair value of extinguished Convertible Senior Notes due 2021 as of December 15, 2020 $ 45.3 Principal of extinguished Convertible Senior Notes due 2021 46.0 Reduction of additional paid-in capital $ (0.7 )
Schedule of Interest Expense	The following table sets forth total interest expense recognized related to the Convertible Notes: Year Ended December 31, 2020 2019 Contractual interest expense $ 5.2 $ 5.2 Amortization of debt issuance costs 0.5 0.4 Amortization of debt discount 4.4 4.0 Total $ 10.1 $ 9.6
Convertible Senior Notes due 2021
Debt Instrument [Line Items]
Schedule of Components of Convertible Notes	The components of the Convertible Senior Notes due 2021 as of December 31, 2020 and December 31, 2019 were as follows: Year Ended December 31, 2020 2019 Principal $ 40.2 $ 86.3 Less: Debt issuance costs, net of amortization (0.1 ) (0.7 ) Less: Debt discount, net of amortization (1.2 ) (7.0 ) Convertible Senior Notes due 2021, net $ 38.9 $ 78.6
Convertible Senior Notes due 2025
Debt Instrument [Line Items]
Schedule of Components of Convertible Notes	The components of the Convertible Senior Notes due 2025 as of December 31, 2020 is as follows: Year Ended December 31, 2020 Principal $ 46.0 Less: Debt issuance costs, net of amortization (1.3 ) Less: Debt discount, net of amortization (5.4 ) Convertible Senior Notes due 2025, net $ 39.3

Retirement and Postretirement_2

Retirement and Postretirement Plans (Tables)	12 Months Ended
	Dec. 31, 2020
Defined Benefit Plans And Other Postretirement Benefit Plans Disclosures [Abstract]
Schedule of Defined Benefit Plans Disclosures	The following tables set forth the change in benefit obligation, change in plan assets, funded status and amounts recognized on the Consolidated Balance Sheets for the defined benefit pension plans as of December 31, 2020 and 2019: Pension Postretirement Change in benefit obligation: 2020 2019 2020 2019 Benefit obligation at the beginning of year $ 1,311.4 $ 1,178.3 $ 126.2 $ 194.7 Service cost 19.4 17.4 1.0 1.1 Interest cost 42.7 48.9 4.2 5.9 Actuarial (gains) losses 114.8 145.7 6.1 11.4 Benefits paid (71.2 ) (72.3 ) (9.2 ) (14.4 ) Plan amendment — (0.7 ) — (72.5 ) Curtailments — (8.9 ) — — Settlements (24.7 ) — — — Foreign currency translation adjustment 2.7 3.0 — — Benefit obligation at the end of year $ 1,395.1 $ 1,311.4 $ 128.3 $ 126.2 Significant actuarial losses related to changes in benefit obligations for 2020 and 2019 primarily resulted from decreases in discount rates. Pension Postretirement Change in plan assets: 2020 2019 2020 2019 Fair value of plan assets at the beginning of year $ 1,155.4 $ 1,054.4 $ 82.3 $ 86.1 Actual return on plan assets 167.0 167.7 7.0 8.9 Company contributions / payments 1.9 2.0 — 1.7 Benefits paid (71.2 ) (72.3 ) (7.1 ) (14.4 ) Settlements (24.7 ) — — — Foreign currency translation adjustment 3.3 3.6 — — Fair value of plan assets at end of year $ 1,231.7 $ 1,155.4 $ 82.2 $ 82.3 Funded status at end of year $ (163.4 ) $ (156.0 ) $ (46.1 ) $ (43.9 )
Schedule of Amounts Recognized in Balance Sheet	Amounts recognized on the balance sheet at December 31, 2020 and 2019 for TimkenSteel’s pension and postretirement benefit plans include: Pension Postretirement 2020 2019 2020 2019 Non-current assets $ 33.5 $ 25.2 $ — $ — Current liabilities (0.6 ) (0.6 ) (1.7 ) (2.4 ) Non-current liabilities (196.3 ) (180.6 ) (44.4 ) (41.5 ) Total $ (163.4 ) $ (156.0 ) $ (46.1 ) $ (43.9 )
Schedule of Amounts Recognized in Other Comprehensive Income (Loss)	Included in accumulated other comprehensive loss at December 31, 2020 and 2019, were the following before-tax amounts that had not been recognized in net periodic benefit cost: Pension Postretirement 2020 2019 2020 2019 Unrecognized prior service (benefit) cost $ 0.2 $ 0.5 $ (61.9 ) $ (67.8 )
Schedule of Assumptions Used	The weighted average assumptions used in determining benefit obligation as of December 31, 2020 and 2019 were as follows: Pension Postretirement Assumptions: 2020 2019 2020 2019 Discount rate 2.68 % 3.42 % 2.65 % 3.42 % Future compensation assumption 2.29 % 2.32 % n/a n/a The weighted average assumptions used in determining benefit cost for the years ended December 31, 2020 and 2019 were as follows: Pension Postretirement Assumptions: 2020 2019 2020 2019 Discount rate ( 1) 3.42 % 4.30 % 3.42 % 4.34% / 3.94% Future compensation assumption 2.32 % 2.36 % n/a n/a Expected long-term return on plan assets 5.80 % 6.41 % 4.50 % 5.00 %
Schedule of Periodic Benefit Cost	The components of net periodic benefit cost (income) for the years ended December 31, 2020, 2019 and 2018 were as follows: Pension Postretirement Years Ended December 31, Years Ended December 31, Components of net periodic benefit cost (income): 2020 2019 2018 2020 2019 2018 Service cost $ 19.4 $ 17.4 $ 17.2 $ 1.0 $ 1.1 $ 1.6 Interest cost 42.7 48.9 45.6 4.2 5.9 7.6 Expected return on plan assets (64.3 ) (65.0 ) (74.0 ) (3.5 ) (3.9 ) (4.8 ) Amortization of prior service cost 0.3 0.4 0.5 (6.0 ) (3.8 ) 0.2 Curtailment — (8.9 ) — — — — Net remeasurement losses (gains) 12.1 43.1 49.1 2.6 6.4 (5.6 ) Net Periodic Benefit Cost (Income) $ 10.2 $ 35.9 $ 38.4 $ (1.7 ) $ 5.7 $ (1.0 )
Schedule of Allocation of Plan Assets	The following table presents the fair value hierarchy for those investments of TimkenSteel’s pension assets measured at fair value on a recurring basis as of December 31, 2020: Total Level 1 Level 2 Level 3 Assets: Cash and cash equivalents $ 9.2 $ 0.9 $ 8.3 $ — U.S government and agency securities 345.7 337.4 8.3 — Corporate bonds 276.9 — 276.9 — Equity securities 68.5 68.5 — — Mutual fund - fixed income 0.1 0.1 — — Mutual fund - equities 22.0 22.0 — — Other 0.2 — 0.2 — Total Assets in the fair value hierarchy $ 722.6 $ 428.9 $ 293.7 $ — Assets measured at net asset value (1) 509.1 — — — Total Assets $ 1,231.7 $ 428.9 $ 293.7 $ — (1) Certain assets that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. Such assets include common collective trusts that invest in equity securities and fixed income securities, limited partnerships, real estate partnerships, hedge funds, and risk parity investments. As of December 31, 2020, these assets are redeemable at net asset value within 90 days. The following table presents the fair value hierarchy for those investments of TimkenSteel’s pension assets measured at fair value on a recurring basis as of December 31, 2019: Total Level 1 Level 2 Level 3 Assets: Cash and cash equivalents $ 12.2 $ 0.9 $ 11.3 $ — U.S government and agency securities 250.3 246.1 4.2 — Corporate bonds 102.7 — 102.7 — Equity securities 49.8 49.8 — — Mutual fund - fixed income 56.4 56.4 — — Total Assets in the fair value hierarchy $ 471.4 $ 353.2 $ 118.2 $ — Assets measured at net asset value (1) 684.0 — — — Total Assets $ 1,155.4 $ 353.2 $ 118.2 $ — (1) Certain assets that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. Such assets include common collective trusts that invest in equity securities and fixed income securities, limited partnerships, real estate partnerships, and risk parity investments. As of December 31, 2019, these assets were redeemable at net asset value within 90 days. The following table presents the fair value hierarchy for those investments of TimkenSteel’s postretirement assets measured at fair value on a recurring basis as of December 31, 2020: Total Level 1 Level 2 Level 3 Assets: Cash and cash equivalents $ 3.0 $ 3.0 $ — $ — Mutual fund - fixed income 11.7 11.7 — — Mutual fund - equities 5.0 5.0 — — Total Assets in the fair value hierarchy $ 19.7 $ 19.7 $ — $ — Assets measured at net asset value (1) 62.5 — — — Total Assets $ 82.2 $ 19.7 $ — $ — (1) Certain assets that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. Such assets include common collective trusts that invest in equity securities and fixed income securities, limited partnerships, real estate partnerships, hedge funds, and risk parity investments. As of December 31, 2020, these assets are redeemable at net asset value within 90 days. The following table presents the fair value hierarchy for those investments of TimkenSteel’s postretirement assets measured at fair value on a recurring basis as of December 31, 2019: Total Level 1 Level 2 Level 3 Assets: Cash and cash equivalents $ 3.0 $ 3.0 $ — $ — Mutual fund - fixed income 15.8 15.8 — — Total Assets in the fair value hierarchy $ 18.8 $ 18.8 $ — $ — Assets measured at net asset value (1) 63.5 — — — Total Assets $ 82.3 $ 18.8 $ — $ — (1) Certain assets that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. Such assets include common collective trusts that invest in equity securities and fixed income securities, limited partnerships, real estate partnerships, and risk parity investments. As of December 31, 2019, these assets were redeemable at net asset value within 90 days.
Schedule of Expected Benefit Payments	Future benefit payments are expected to be as follows: Benefit Payments: Pension Postretirement 2021 $ 79.1 $ 11.1 2022 86.2 10.3 2023 81.6 9.5 2024 74.5 8.8 2025 74.3 8.4 2026-2030 366.0 37.9

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2020
Assumptions Used in Calculating Fair Value of Options	The following table provides the significant assumptions used to calculate the grant date fair values of stock options granted using a Black-Scholes option pricing method: 2020 2019 2018 Weighted-average fair value per option $ 2.23 $ 5.54 $ 7.46 Risk-free interest rate 0.96 % 2.63 % 2.77 % Dividend yield — % — % — % Expected stock volatility 42.67 % 41.36 % 41.67 % Expected life - years 6 6 6
Share-based Compensation, Stock Options, Activity	The following summarizes TimkenSteel stock option activity from January 1, 2020 to December 31, 2020: Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (millions) Outstanding as of December 31, 2019 2,641,570 $ 20.64 Granted 511,020 $ 5.26 Exercised — $ — Canceled, forfeited or expired (221,525 ) $ 12.08 Outstanding as of December 31, 2020 2,931,065 $ 18.61 5.2 $ — Options expected to vest 641,392 $ 8.21 8.7 $ — Options exercisable 2,289,673 $ 21.52 4.2 $ —
Time-Based Restricted Stock Units
Nonvested Restricted Stock Shares Activity	The following summarizes TimkenSteel stock-settled, time-based restricted stock unit activity from January 1, 2020 to December 31, 2020: Number of Shares Weighted Average Grant Date Fair Value Outstanding as of December 31, 2019 1,103,487 $ 11.89 Granted 931,244 $ 4.24 Vested (548,301 ) $ 10.55 Canceled, forfeited or expired (114,104 ) $ 7.23 Outstanding as of December 31, 2020 1,372,326 $ 7.62
Performance-Based Restricted Stock Units
Nonvested Restricted Stock Shares Activity	The following summarizes TimkenSteel stock-settled performance-based restricted stock unit activity from January 1, 2020 to December 31, 2020: Number of Shares Weighted Average Grant Date Fair Value Outstanding as of December 31, 2019 — $ — Granted 182,180 $ 4.98 Canceled, forfeited or expired (6,216 ) $ 4.97 Outstanding as of December 31, 2020 175,964 $ 4.98

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2020
Accumulated Other Comprehensive Income Loss Net Of Tax [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	Changes in accumulated other comprehensive income (loss) for the years ended December 31, 2020 and 2019 by component were as follows: Foreign Currency Translation Adjustments Pension and Postretirement Liability Adjustments Total Balance as of December 31, 2019 $ (6.8 ) $ 51.5 $ 44.7 Other comprehensive income before reclassifications, before income tax 1.4 — 1.4 Amounts reclassified from accumulated other comprehensive income (loss), before income tax — (5.6 ) (5.6 ) Tax effect — (0.1 ) (0.1 ) Net current period other comprehensive income, net of income taxes 1.4 (5.7 ) (4.3 ) Balance as of December 31, 2020 $ (5.4 ) $ 45.8 $ 40.4 Foreign Currency Translation Adjustments Pension and Postretirement Liability Adjustments Total Balance at December 31, 2018 $ (7.3 ) $ (1.6 ) $ (8.9 ) Other comprehensive income before reclassifications, before income tax 0.5 — 0.5 Amounts reclassified from accumulated other comprehensive income (loss), before income tax — (2.4 ) (2.4 ) Amounts deferred to accumulated other comprehensive income (loss), before income tax — 72.2 72.2 Tax effect — (16.7 ) (16.7 ) Net current period other comprehensive income, net of income taxes 0.5 53.1 53.6 Balance as of December 31, 2019 $ (6.8 ) $ 51.5 $ 44.7

Selected Quarterly Financial _2

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Data	The following is selected quarterly operating results for each quarter of fiscal 2020 and 2019 for TimkenSteel. Quarters ended December 31, 2020 September 30, 2020 June 30, 2020 March 31, 2020 Net sales $ 211.2 $ 205.9 $ 154.0 $ 259.7 Gross profit 14.2 (2.4 ) (4.0 ) 7.8 Net income (loss) (12.8 ) (13.9 ) (15.3 ) (19.9 ) Per share data: Basic earnings (loss) per share $ (0.28 ) $ (0.31 ) $ (0.34 ) $ (0.44 ) Diluted earnings (loss) per share $ (0.28 ) $ (0.31 ) $ (0.34 ) $ (0.44 ) Quarters ended December 31, 2019 September 30. 2019 June 30, 2019 March 31, 2019 Net sales $ 226.9 $ 274.2 $ 336.7 $ 371.0 Gross profit (18.0 ) (2.6 ) 14.8 28.4 Net income (loss) (84.6 ) (17.0 ) (11.9 ) 3.5 Per share data: Basic earnings (loss) per share $ (1.89 ) $ (0.38 ) $ (0.27 ) $ 0.08 Diluted earnings (loss) per share $ (1.89 ) $ (0.38 ) $ (0.27 ) $ 0.08

Basis of Presentation Narrative

Basis of Presentation Narrative (Details) T in Millions	12 Months Ended
	Dec. 31, 2020T
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Annual Melt Capacity	2
Annual Shipment Capacity	1.5

Significant Accounting Polici_3

Significant Accounting Policies - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Warranty claims	$ 0	$ 0	$ 0
Foreign currency exchange gains (losses)	(200,000)	0	(200,000)
Research and development	$ 1,800,000	$ 4,100,000	$ 8,100,000
ASU 2020-04
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Change In Accounting Principle Accounting Standards Update Adopted	true
Change in accounting principle, accounting standards update, immaterial effect	true
Change in accounting principle, accounting standards update, adoption date	Mar. 12, 2020
ASU 2018-14
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Change In Accounting Principle Accounting Standards Update Adopted	true
Change in accounting principle, accounting standards update, immaterial effect	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2020
ASU 2018-15
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Change In Accounting Principle Accounting Standards Update Adopted	true
Change in accounting principle, accounting standards update, immaterial effect	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2020
ASU 2018-13
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Change In Accounting Principle Accounting Standards Update Adopted	true
Change in accounting principle, accounting standards update, immaterial effect	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2020
ASU 2016-13
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Change In Accounting Principle Accounting Standards Update Adopted	true
Change in accounting principle, accounting standards update, immaterial effect	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2020
Building
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Useful lives of property, plant and equipment, net	30 years
Minimum
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Useful lives of intangible asses, net	3 years
Minimum | Machinery and Equipment
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Useful lives of property, plant and equipment, net	3 years
Maximum
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Useful lives of intangible asses, net	15 years
Maximum | Machinery and Equipment
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Useful lives of property, plant and equipment, net	20 years

Segment Information (Details)

Segment Information (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	$ 211.2	$ 205.9	$ 154	$ 259.7	$ 226.9	$ 274.2	$ 336.7	$ 371	$ 830.7	$ 1,208.8	$ 1,610.6
Long-lived assets, net	600.1				655				600.1	655
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									746.8	1,096.8	1,456.2
Long-lived assets, net	599.1				654.8				599.1	654.8
Foreign
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									83.9	112	$ 154.4
Long-lived assets, net	$ 1				$ 0.2				$ 1	$ 0.2

Revenue Recognition (Details)

Revenue Recognition (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Net sales	$ 211.2	$ 205.9	$ 154	$ 259.7	$ 226.9	$ 274.2	$ 336.7	$ 371	$ 830.7	$ 1,208.8	$ 1,610.6
Bar
Disaggregation of Revenue [Line Items]
Net sales									502.5	783	1,030.7
Tube
Disaggregation of Revenue [Line Items]
Net sales									101.4	151.8	254.7
Value-add
Disaggregation of Revenue [Line Items]
Net sales									208.1	240.6	284.3
Other
Disaggregation of Revenue [Line Items]
Net sales									18.7	33.4	40.9
Mobile
Disaggregation of Revenue [Line Items]
Net sales									346	479.3	553.9
Industrial
Disaggregation of Revenue [Line Items]
Net sales									391.7	486.3	637.5
Energy
Disaggregation of Revenue [Line Items]
Net sales									53.2	166.4	265.6
Other
Disaggregation of Revenue [Line Items]
Net sales									$ 39.8	$ 76.8	$ 153.6

Restructuring Charges - Narrati

Restructuring Charges - Narrative (Details) $ in Millions	12 Months Ended			24 Months Ended
	Dec. 31, 2020USD ($)Position	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2020Position
Restructuring And Related Activities [Abstract]
Number of positions eliminated | Position	55			215
Restructuring charges	$ 3.1	$ 8.6	$ 0
Accelerated restructuring charges	$ 0.1	$ 0.3

Restructuring Charges - Summary

Restructuring Charges - Summary of Restructuring Reserve (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring Reserve [Roll Forward]
Beginning balance	$ 6
Expenses	3.1	$ 8.6	$ 0
Payments	(7.6)	(2.6)
Ending balance	$ 1.5	$ 6

Disposition of Non-Core Assets

Disposition of Non-Core Assets (Details) - USD ($) $ in Millions	3 Months Ended			12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Jun. 30, 2020
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Assets held for sale			$ 4.1	$ 0.3	$ 4.1
Inventory valuation reserves			10.7	13.9	10.7
Scrap Processing Facility
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Inventory valuation reserves			4.8		4.8
Disposal Group, Held-for-sale, Not Discontinued Operation
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Impairment charges and loss on sale or disposal of assets			7.3
Gain (loss) on sale/disposal		$ 0.1		3.6
Accelerated depreciation		$ 1.6	2.8
Inventory write-down					4.8
Inventory valuation reserves						$ 3.1
Disposal Group, Held-for-sale, Not Discontinued Operation | Canton, Ohio
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Gain (loss) on sale/disposal				0.5
Disposal Group, Held-for-sale, Not Discontinued Operation | Machinery and Equipment
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Accelerated depreciation				1.8
Assets held for sale				$ 0.3
Disposal Group, Held-for-sale, Not Discontinued Operation | Machinery and Equipment | Scenario, Forecast
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Accelerated depreciation	$ 1.3
Disposal Group, Held-for-sale, Not Discontinued Operation | Scrap Processing Facility
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Disposal group consideration			4		$ 4
Disposal Group, Held-for-sale, Not Discontinued Operation | Inventories
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Impairment charges and loss on sale or disposal of assets			$ 11.3

Other (Income) Expense , Net (D

Other (Income) Expense , Net (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other Income And Expenses [Abstract]
Pension and postretirement non-service benefit (income) loss	$ (26.6)	$ (17.5)	$ (25.2)
Loss (gain) from remeasurement of benefit plans	14.7	40.6	43.5
Foreign currency exchange loss (gain)	0.2	0	0.2
Employee retention credit	(2.3)
Miscellaneous (income) expense	(0.2)	0.2	0.1
Total other (income) expense, net	$ (14.2)	$ 23.3	$ 18.6

Other (Income) Expense , Net -

Other (Income) Expense , Net - Narrative (Details) - Coronavirus Aid Relief And Economic Security Act	12 Months Ended
	Dec. 31, 2020USD ($)Installment
Statutory Accounting Practices [Line Items]
Percentage of employee wages deferred as employer share of payroll taxes	6.20%
Deferred cash payments of payroll taxes	$ 6,400,000
Number of installments, deferred cash payments of payroll taxes to be paid | Installment	2
Percentage of tax credit	0.50
Accrued benefit	$ 2,300,000
Qualified wages per employee	10,000
Maximum
Statutory Accounting Practices [Line Items]
Employee retention credit refundable tax credit for eligible employers	$ 5,000

Income Tax Provision - Income f

Income Tax Provision - Income from Operations Before Income Taxes Based on Geographic Location of Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
United States	$ (64.1)	$ (130.8)	$ (10.1)
Non-United States	3.4	4.7	1.9
Loss from operations before income taxes	$ (60.7)	$ (126.1)	$ (8.2)

Income Tax Provision - (Benefit

Income Tax Provision - (Benefit) Provision for Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current:
Federal	$ 0.6
State and local		$ 0.1	$ 0.3
Foreign	0.5	0.4	0.7
Current tax provision (benefit)	1.1	0.5	1
Deferred:
Federal	(0.4)	(14.4)	0.4
State and local	0.5	(2)
Foreign		(0.2)	0.4
Deferred tax provision (benefit)	0.1	(16.6)	0.8
Provision (benefit) for incomes taxes	$ 1.2	$ (16.1)	$ 1.8

Income Tax Provision - Narrativ

Income Tax Provision - Narrative (Details) - USD ($)	3 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Loss Carryforwards [Line Items]
Dividends declared	$ 5,100,000
Undistributed Earnings of Foreign Subsidiaries		$ 2,700,000	$ 6,500,000	$ 5,500,000
Deferred Tax Liabilities, Undistributed Foreign Earnings		300,000	700,000
Deferred income taxes		1,000,000	900,000
Operating Loss Carryforwards		406,800,000
Operating Loss Carryforwards, Valuation Allowance		47,700,000
Unrecognized Tax Benefits		0	0	0
Unrecognized Tax Benefits that Would Impact Effective Tax Rate		0	0	0
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued		0	0	$ 0
Foreign
Operating Loss Carryforwards [Line Items]
Income Taxes Paid		400,000	600,000
Withholding taxes paid for cash repatriation	500,000
Operating Loss Carryforwards		58,500,000
State
Operating Loss Carryforwards [Line Items]
Income Taxes Paid		100,000	200,000
Income Taxes Receivable, Current		0	0
U.S.
Operating Loss Carryforwards [Line Items]
Income Taxes Paid		0	$ 0
Withholding taxes paid for cash repatriation	$ 4,600,000
Operating Loss Carryforwards		$ 348,300,000

Income Tax Provision - Reconcil

Income Tax Provision - Reconciliation Between Effective Tax Rate and Statutory Rate (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
U.S. federal income tax provision (benefit) at statutory rate	$ (12.7)	$ (26.5)	$ (6.3)
Adjustments:
State and local income taxes, net of federal tax benefit	2.3	(1.3)	(0.5)
Foreign earnings taxed at different rates	0.1		0.2
U.S. research tax credit		0.2	(0.2)
Valuation allowance	10.3	10.2	7.5
Global intangible low-taxed income		0.2	0.5
Permanent differences	1.3	1.3	0.8
Other items, net	(0.1)	(0.2)	(0.2)
Provision (benefit) for incomes taxes	$ 1.2	$ (16.1)	$ 1.8
Effective tax rate	(2.00%)	12.80%	(5.90%)

Income Tax Provision - Effect o

Income Tax Provision - Effect of Temporary Differences Giving Rise to Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Deferred tax liabilities:
Depreciation	$ (97.5)	$ (98.6)
Inventory	(16.2)	(24.3)
Convertible debt	(1.6)	(1.7)
Leases - right-of-use asset	(5)	(3.4)
Other, net	(0.3)	(0.7)
Deferred tax liabilities	(120.6)	(128.7)
Deferred tax assets:
Pension and postretirement benefits	50.3	47.9
Other employee benefit accruals	8.7	7.2
Tax loss carryforwards	94.4	86
Intangible assets	1	1.1
Inventory	4.5	5.4
State decoupling	2.8	4.5
Lease liability	5	3.4
Interest limitation		6
Other, net	0.6	1.2
Deferred tax assets subtotal	167.3	162.7
Valuation allowances	(47.7)	(34.9)
Deferred tax assets	119.6	127.8
Net deferred tax assets (liabilities)	$ (1)	$ (0.9)

Earnings (Loss) Per Share - Add

Earnings (Loss) Per Share - Additional Information (Details) - shares shares in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Equity-based Awards [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation	4.6	3.7	3.3
Convertible Notes [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation	9.1	6.9	6.9

Earnings (Loss) Per Share - Sch

Earnings (Loss) Per Share - Schedule of Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Numerator:
Net income (loss)	$ (12.8)	$ (13.9)	$ (15.3)	$ (19.9)	$ (84.6)	$ (17)	$ (11.9)	$ 3.5	$ (61.9)	$ (110)	$ (10)
Denominator:
Weighted average shares outstanding, basic									45	44.8	44.6
Weighted average shares outstanding, diluted									45	44.8	44.6
Basic earnings (loss) per share	$ (0.28)	$ (0.31)	$ (0.34)	$ (0.44)	$ (1.89)	$ (0.38)	$ (0.27)	$ 0.08	$ (1.38)	$ (2.46)	$ (0.22)
Diluted earnings (loss) per share	$ (0.28)	$ (0.31)	$ (0.34)	$ (0.44)	$ (1.89)	$ (0.38)	$ (0.27)	$ 0.08	$ (1.38)	$ (2.46)	$ (0.22)

Inventories - Schedule of Inven

Inventories - Schedule of Inventory (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Inventory Disclosure [Abstract]
Manufacturing supplies	$ 37.6	$ 49.8
Raw materials	20	26
Work in process	79.1	123.7
Finished products	55.6	93.1
Gross inventory	192.3	292.6
Allowance for inventory reserves	(13.9)	(10.7)
Total inventories, net	$ 178.4	$ 281.9

Inventories - Narrative (Detail

Inventories - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2020	Jun. 30, 2020	Dec. 31, 2019
Inventory [Line Items]
Inventory valuation reserves	$ 13.9		$ 10.7
Scrap Processing Facility
Inventory [Line Items]
Inventory valuation reserves			$ 4.8
Disposal Group, Held-for-sale, Not Discontinued Operation
Inventory [Line Items]
Inventory valuation reserves		$ 3.1

Property, Plant and Equipment -

Property, Plant and Equipment - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Abstract]
Land	$ 13.3	$ 13.3
Buildings and improvements	422.5	419
Machinery and equipment	1,398.7	1,404.6
Construction in progress	11	30.9
Subtotal	1,845.5	1,867.8
Less allowances for depreciation	(1,275.7)	(1,241.4)
Property, plant and equipment, net	$ 569.8	$ 626.4

Property, Plant and Equipment_2

Property, Plant and Equipment - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property Plant And Equipment [Abstract]
Depreciation	$ 65	$ 67.4	$ 67.5
Accelerated depreciation	2.4	1.9
Impairment charges and loss on sale	$ 2.6	$ 9	$ 0.5

Intangible Assets - Schedule of

Intangible Assets - Schedule of Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 73.3	$ 76.4
Accumulated Amortization	64	62.1
Net Carrying Amount	9.3	14.3
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	6.3	6.3
Accumulated Amortization	5.4	5
Net Carrying Amount	0.9	1.3
Technology use
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	9	9
Accumulated Amortization	9	8
Net Carrying Amount		1
Capitalized software
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	58	61.1
Accumulated Amortization	49.6	49.1
Net Carrying Amount	$ 8.4	$ 12

Intangible Assets - Narrative (

Intangible Assets - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Weighted average remaining useful life	8 years
Amortization expense for intangible assets	$ 5	$ 6.1	$ 5.5
Loss on disposal of intangibles	$ 0.2	0.1	$ 0.4
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Weighted average remaining useful life	15 years
Technology use
Finite-Lived Intangible Assets [Line Items]
Weighted average remaining useful life	15 years
Capitalized software
Finite-Lived Intangible Assets [Line Items]
Weighted average remaining useful life	6 years
Accelerated amortization expense	$ 1	$ 0.9

Intangible Assets - Estimated A

Intangible Assets - Estimated Annual Amortization Expense (Details) $ in Millions	Dec. 31, 2020USD ($)
Goodwill And Intangible Assets Disclosure [Abstract]
2021	$ 3.1
2022	2.6
2023	2
2024	1
2025	$ 0.1

Leases - Narrative (Details)

Leases - Narrative (Details)	12 Months Ended
	Dec. 31, 2020USD ($)
Lessee, Lease, Description [Line Items]
Lessee, operating lease, option to extend	true
Extension term	1 year
Financing leases	$ 0
Weighted average remaining lease term for operating leases	3 years 4 months 24 days
Weighted average discount rate used to measure operating lease liabilities	3.20%
Leases not yet commenced	$ 0
Minimum
Lessee, Lease, Description [Line Items]
Remaining lease term	1 year
Maximum
Lessee, Lease, Description [Line Items]
Remaining lease term	6 years

Leases - Lease Cost (Details)

Leases - Lease Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating lease cost	$ 8.8	$ 7.4
Short-term lease cost	0.7	1.9
Total lease cost	$ 9.5	$ 9.3

Leases - Supplemental Cash Flow

Leases - Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Cash paid for amounts included in the measurement of operating lease liabilities	$ 8.8	$ 7.5
Right-of-use assets obtained in exchange for operating lease obligations	$ 12.5	$ 4.3

Leases - Future Minimum Lease P

Leases - Future Minimum Lease Payments (Details) $ in Millions	Dec. 31, 2020USD ($)
Leases [Abstract]
2021	$ 8.4
2022	5.7
2023	4.8
2024	2.7
After 2024	0.9
Total future minimum lease payments	22.5
Less amount of lease payment representing interest	(1.5)
Total present value of lease payments	$ 21

Financing Arrangements - Summar

Financing Arrangements - Summary of Current and Non-current Debt (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 15, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Total debt	$ 78.2		$ 168.6
Less current portion of debt	38.9
Total non-current portion of debt	39.3		168.6
Credit Agreement
Debt Instrument [Line Items]
Total debt			90
Convertible Senior Notes due 2021
Debt Instrument [Line Items]
Total debt	38.9		78.6
Convertible Senior Notes due 2025
Debt Instrument [Line Items]
Total debt	$ 39.3	$ 40.6	$ 0

Financing Arrangements - Narrat

Financing Arrangements - Narrative (Details)	Dec. 15, 2020USD ($)$ / shares	Oct. 15, 2019USD ($)	Dec. 31, 2020USD ($)	May 31, 2016USD ($)$ / shares	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Debt Instrument [Line Items]
Initial value of principal			$ 78,200,000		$ 78,200,000	$ 168,600,000
Interest paid					7,600,000	11,500,000
Decrease to additional paid in capital					10,600,000
Increase to current convertible notes net					1,100,000
Increase to non-current convertible notes net					5,300,000
Retained deficit			(363,400,000)		(363,400,000)	(301,500,000)
Cumulative Effect, Period of Adoption, Adjustment
Debt Instrument [Line Items]
Retained deficit			4,300,000		$ 4,300,000
Third Amended Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, tentative future commitment increase		$ 100,000,000
Line of credit facility, unused capacity, commitment fee percentage		0.25%
Maturity date					Oct. 15, 2024
Convertible Senior Notes due 2021, Issuance One | Convertible Notes
Debt Instrument [Line Items]
Debt Instrument, Face Amount				$ 75,000,000
Convertible Senior Notes due 2021, Over-allotment | Convertible Notes
Debt Instrument [Line Items]
Debt Instrument, Face Amount				11,300,000
Convertible Senior Notes due 2021
Debt Instrument [Line Items]
Maturity date					Jun. 1, 2021
Initial value of principal			38,900,000	$ 66,900,000	$ 38,900,000	78,600,000
Effective interest rate				12.00%
Principal amount allocated to conversion feature				$ 19,400,000
Transaction costs, debt			100,000	2,400,000	100,000	700,000
Transaction costs, equity component of convertible debt				$ 700,000
Exchange of aggregate principal amount			46,000,000
Convertible senior notes deemed to be extinguished			46,000,000
Convertible Senior Notes due 2021 | Convertible Notes
Debt Instrument [Line Items]
Maturity date				Jun. 1, 2021
Debt instrument, interest rate, stated percentage				6.00%
Debt instrument interest payment dates description				June 1 and December 1 of each year, beginning on December 1, 2016
Debt instrument, convertible, conversion price | $ / shares				$ 12.58
Debt instrument, convertible, conversion ratio				0.0795165
Debt instrument, convertible, amounts by which instrument can be converted				$ 1,000
Proceeds from convertible debt				$ 83,200,000
Convertible Senior Notes due 2025
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity			$ 46,000,000		$ 46,000,000
Maturity date	Dec. 1, 2025
Debt instrument, interest rate, stated percentage	6.00%		6.00%		6.00%
Debt instrument interest payment dates description	June 1 and December 1 of each year, beginning on December 1, 2021
Debt instrument, convertible, conversion price | $ / shares	$ 7.82
Debt instrument, convertible, conversion ratio	0.1278119
Debt instrument, convertible, amounts by which instrument can be converted	$ 1,000
Initial value of principal	$ 40,600,000		$ 39,300,000		$ 39,300,000	0
Effective interest rate	9.00%
Principal amount allocated to conversion feature	$ 5,500,000
Transaction costs, debt	1,300,000		1,300,000		1,300,000
Transaction costs, equity component of convertible debt	200,000
Cash proceeds from issuance of convertible senior notes			$ 0
Percentage of different from present value of remaining cash flows of convertible senior notes			10.00%
Fair value of convertible notes			$ 39,300,000		39,300,000
Outstanding borrowings			0		0
Convertible Senior Notes due 2021
Debt Instrument [Line Items]
Initial value of principal			$ 38,900,000		38,900,000	78,600,000
Fair value of extinguished portion calculated using market rate			9.00%
Debt instrument remaining term			5 months 15 days
Remaining accrued and unpaid interest of debt	46,000,000
Payment of accrued and unpaid interest of debt	100,000
Fair value of convertible notes			$ 34,600,000		34,600,000
Decrease to additional paid in capital	$ (700,000)
Credit Agreement
Debt Instrument [Line Items]
Initial value of principal						$ 90,000,000
Credit Agreement | Third Amended Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity		$ 400,000,000
Amount available under amended credit agreement			$ 211,300,000		$ 211,300,000
Commercial and Standby Letters of Credit | Third Amended Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, borrowing sublimit		15,000,000
Swingline Loans | Third Amended Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, borrowing sublimit		$ 40,000,000
Swingline Loans | Third Amended Credit Facility [Member] | Federal Reserve Bank of New York Rate
Debt Instrument [Line Items]
Variable interest rate, spread		0.50%
Swingline Loans | Third Amended Credit Facility [Member] | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Variable interest rate, spread		1.00%
First In, Last Out (FILO) | Third Amended Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, tentative future commitment increase		$ 30,000,000

Financing Arrangements - Schedu

Financing Arrangements - Schedule of Net Carrying Amount of Extinguished Convertible Senior Notes (Details) - USD ($) $ in Millions	Dec. 15, 2020	Dec. 31, 2020
Debt Instrument [Line Items]
Loss on extinguishment of debt		$ (0.9)
Convertible Senior Notes due 2021
Debt Instrument [Line Items]
Principal	$ 46
Less: Debt issuance costs, net of amortization	(0.1)
Less: Debt discount, net of amortization	(1.5)
Fair value of extinguished Convertible Senior Notes due 2021 as of December 15, 2020	45.3
Loss on extinguishment of debt	$ (0.9)

Financing Arrangements - Sche_2

Financing Arrangements - Schedule of Amount Allocated to Reacquisition of Equity Component Included as Reduction To Additional Paid-In Capital (Details) - USD ($) $ in Millions	Dec. 15, 2020	Dec. 31, 2020
Debt Instrument [Line Items]
Reduction of additional paid-in capital		$ 10.6
Convertible Senior Notes due 2021
Debt Instrument [Line Items]
Fair value of extinguished Convertible Senior Notes due 2021 as of December 15, 2020	$ 45.3
Principal of extinguished Convertible Senior Notes due 2021	46
Reduction of additional paid-in capital	$ (0.7)

Financing Arrangements - Sche_3

Financing Arrangements - Schedule of Convertible Debt (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 15, 2020	Dec. 31, 2019	May 31, 2016
Debt Instrument [Line Items]
Total debt	$ 78.2		$ 168.6
Convertible Senior Notes due 2021
Debt Instrument [Line Items]
Principal	40.2		86.3
Less: Debt issuance costs, net of amortization	(0.1)		(0.7)	$ (2.4)
Less: Debt discount, net of amortization	(1.2)		(7)
Total debt	38.9		78.6	$ 66.9
Convertible Senior Notes due 2025
Debt Instrument [Line Items]
Principal	46
Less: Debt issuance costs, net of amortization	(1.3)	$ (1.3)
Less: Debt discount, net of amortization	(5.4)
Total debt	$ 39.3	$ 40.6	$ 0

Financing Arrangements - Sche_4

Financing Arrangements - Schedule of Interest Expense (Details) - Convertible Notes - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Contractual interest expense	$ 5.2	$ 5.2
Amortization of debt issuance costs	0.5	0.4
Amortization of debt discount	4.4	4
Total	$ 10.1	$ 9.6

Retirement and Postretirement_3

Retirement and Postretirement Plans - Narrative (Details) $ in Millions	3 Months Ended	12 Months Ended
	Jun. 30, 2019USD ($)	Dec. 31, 2020USD ($)Plan	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Benefit cost amortization period			12 years
Pension cost and other postretirement benefits cost (reversal of cost), remeasurement		$ 14.7	$ 40.6	$ 43.5
Defined contribution plan cost		$ 3.2	7.1	$ 6.3
Equity securities
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Target asset allocation		21.00%
Debt Securities
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Target asset allocation		61.00%
Other Investments
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Target asset allocation		18.00%
Postretirement
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, accumulated benefit obligation, increase (decrease) for plan amendment	$ (70.2)		(70.2)
Reduction of future liability			8.1
TimkenSteel Corporation Bargaining Unit Welfare Plan for Retirees
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension cost and other postretirement benefits cost (reversal of cost), remeasurement			4.4
Pension
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Reduction of future liability			0.8
Settlements		$ 24.7
Retirement plan expenses		$ 3.8	3.5
Number of plans for which the accumulated benefit obligation exceeded the fair value of plan assets | Plan		2
Benefit obligation for plans which the accumulated benefit obligation exceeded the fair value of plan assets		$ 1,081.2
Accumulated benefit obligation for plans which the accumulated benefit obligation exceeded the fair value of plan assets		1,063.9
Fair value of plan assets for plan which the accumulated benefit obligation exceeded the fair value of plan assets		884.3
Accumulated benefit obligation		1,377.6	1,294.5
Pension | U.K.
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected contributions in next fiscal year		$ 1.4
Wellfare Benefit Plan
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Reduction of future postretirement liability			$ 2.3
Medical and Prescription Drug Benefits
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Health care cost trend rate		5.50%	5.75%

Retirement and Postretirement_4

Retirement and Postretirement Plans - Change in Benefit Obligations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Pension
Change in benefit obligation:
Benefit obligation at the beginning of year	$ 1,311.4	$ 1,178.3
Service cost	19.4	17.4	$ 17.2
Interest cost	42.7	48.9	45.6
Actuarial (gains) losses	114.8	145.7
Benefits paid	(71.2)	(72.3)
Plan amendment		(0.7)
Curtailments		(8.9)
Settlements	(24.7)
Foreign currency translation adjustment	2.7	3
Benefit obligation at the end of year	1,395.1	1,311.4	1,178.3
Postretirement
Change in benefit obligation:
Benefit obligation at the beginning of year	126.2	194.7
Service cost	1	1.1	1.6
Interest cost	4.2	5.9	7.6
Actuarial (gains) losses	6.1	11.4
Benefits paid	(9.2)	(14.4)
Plan amendment		(72.5)
Benefit obligation at the end of year	$ 128.3	$ 126.2	$ 194.7

Retirement and Postretirement_5

Retirement and Postretirement Plans - Change in Plan Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Pension
Change in plan assets:
Fair value of plan assets at the beginning of year	$ 1,155.4	$ 1,054.4
Actual return on plan assets	167	167.7
Company contributions / payments	1.9	2
Benefits paid	(71.2)	(72.3)
Settlements	(24.7)
Foreign currency translation adjustment	3.3	3.6
Fair value of plan assets at end of year	1,231.7	1,155.4
Funded status at end of year	(163.4)	(156)
Postretirement
Change in plan assets:
Fair value of plan assets at the beginning of year	82.3	86.1
Actual return on plan assets	7	8.9
Company contributions / payments		1.7
Benefits paid	(7.1)	(14.4)
Fair value of plan assets at end of year	82.2	82.3
Funded status at end of year	$ (46.1)	$ (43.9)

Retirement and Postretirement_6

Retirement and Postretirement Plans - Amounts Recognized in the Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Non-current assets	$ 33.5	$ 25.2
Current liabilities	(2.3)	(3)
Non-current liabilities	(240.7)	(222.1)
Pension
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Non-current assets	33.5	25.2
Current liabilities	(0.6)	(0.6)
Non-current liabilities	(196.3)	(180.6)
Total assets (liabilities) recognized	(163.4)	(156)
Postretirement
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Current liabilities	(1.7)	(2.4)
Non-current liabilities	(44.4)	(41.5)
Total assets (liabilities) recognized	$ (46.1)	$ (43.9)

Retirement and Postretirement_7

Retirement and Postretirement Plans - Amounts Recognized in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Pension
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Unrecognized prior service (benefit) cost	$ 0.2	$ 0.5
Postretirement
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Unrecognized prior service (benefit) cost	$ (61.9)	$ (67.8)

Retirement and Postretirement_8

Retirement and Postretirement Plans - Weighted Average Assumptions (Details)	4 Months Ended	8 Months Ended	12 Months Ended
	Apr. 30, 2019	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Pension
Benefit Obligation
Discount rate		3.42%	2.68%	3.42%
Future compensation assumption		2.32%	2.29%	2.32%
Benefit Cost
Discount rate			3.42%	4.30%
Future compensation assumption			2.32%	2.36%
Expected long-term return on plan assets			5.80%	6.41%
Postretirement
Benefit Obligation
Discount rate		3.42%	2.65%	3.42%
Benefit Cost
Discount rate	4.34%	3.94%	3.42%
Expected long-term return on plan assets			4.50%	5.00%
Postretirement | Minimum
Benefit Cost
Discount rate				4.34%
Postretirement | Maximum
Benefit Cost
Discount rate				3.94%

Retirement and Postretirement_9

Retirement and Postretirement Plans - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Pension
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 19.4	$ 17.4	$ 17.2
Interest cost	42.7	48.9	45.6
Expected return on plan assets	(64.3)	(65)	(74)
Amortization of prior service cost	0.3	0.4	0.5
Curtailments		(8.9)
Net remeasurement losses (gains)	12.1	43.1	49.1
Net Periodic Benefit Cost (Income)	10.2	35.9	38.4
Postretirement
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	1	1.1	1.6
Interest cost	4.2	5.9	7.6
Expected return on plan assets	(3.5)	(3.9)	(4.8)
Amortization of prior service cost	(6)	(3.8)	0.2
Net remeasurement losses (gains)	2.6	6.4	(5.6)
Net Periodic Benefit Cost (Income)	$ (1.7)	$ 5.7	$ (1)

Retirement and Postretiremen_10

Retirement and Postretirement Plans - Allocation of Plan Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Pension
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	$ 1,231.7	$ 1,155.4	$ 1,054.4
Pension | Level 1, 2 and 3
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	722.6	471.4
Pension | Level 1, 2 and 3 | Cash and cash equivalents
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	9.2	12.2
Pension | Level 1, 2 and 3 | U.S government and agency securities
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	345.7	250.3
Pension | Level 1, 2 and 3 | Corporate bonds
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	276.9	102.7
Pension | Level 1, 2 and 3 | Equity securities
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	68.5	49.8
Pension | Level 1, 2 and 3 | Mutual fund - fixed income
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	0.1	56.4
Pension | Level 1, 2 and 3 | Mutual fund - equities
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	22
Pension | Level 1, 2 and 3 | Other
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	0.2
Pension | Level 1
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	428.9	353.2
Pension | Level 1 | Cash and cash equivalents
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	0.9	0.9
Pension | Level 1 | U.S government and agency securities
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	337.4	246.1
Pension | Level 1 | Equity securities
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	68.5	49.8
Pension | Level 1 | Mutual fund - fixed income
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	0.1	56.4
Pension | Level 1 | Mutual fund - equities
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	22
Pension | Level 2
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	293.7	118.2
Pension | Level 2 | Cash and cash equivalents
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	8.3	11.3
Pension | Level 2 | U.S government and agency securities
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	8.3	4.2
Pension | Level 2 | Corporate bonds
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	276.9	102.7
Pension | Level 2 | Other
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	0.2
Pension | Assets measured at net asset value
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	$ 509.1	$ 684
Redemption period	90 days	90 days
Postretirement
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	$ 82.2	$ 82.3	$ 86.1
Postretirement | Level 1, 2 and 3
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	19.7	18.8
Postretirement | Level 1, 2 and 3 | Cash and cash equivalents
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	3	3
Postretirement | Level 1, 2 and 3 | Mutual fund - fixed income
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	11.7	15.8
Postretirement | Level 1, 2 and 3 | Mutual fund - equities
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	5
Postretirement | Level 1
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	19.7	18.8
Postretirement | Level 1 | Cash and cash equivalents
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	3	3
Postretirement | Level 1 | Mutual fund - fixed income
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	11.7	15.8
Postretirement | Level 1 | Mutual fund - equities
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	5
Postretirement | Assets measured at net asset value
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Total Assets	$ 62.5	$ 63.5
Redemption period	90 days	90 days

Retirement and Postretiremen_11

Retirement and Postretirement Plans - Benefit Payments (Details) $ in Millions	Dec. 31, 2020USD ($)
Pension
Benefit Payments:
2021	$ 79.1
2022	86.2
2023	81.6
2024	74.5
2025	74.3
2026-2030	366
Postretirement
Benefit Payments:
2021	11.1
2022	10.3
2023	9.5
2024	8.8
2025	8.4
2026-2030	$ 37.9

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details)	Dec. 16, 2020USD ($)$ / sharesshares	May 06, 2020USD ($)shares	Apr. 28, 2016shares	Dec. 31, 2020USD ($)$ / sharesshares	Dec. 31, 2019USD ($)$ / shares	Dec. 31, 2018USD ($)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options exercised				0
Stock-based compensation expense | $				$ 6,600,000	$ 7,400,000	$ 7,300,000
Future stock-based compensation expense | $				$ 6,100,000
Future stock-based compensation expense, period of recognition				1 year 6 months
Time-Based Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting rights description				These restricted stock units do not have any performance conditions for vesting.
Weighted average grant date fair value | $ / shares				$ 7.62	$ 11.89
Performance-Based Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting rights description				The overall vesting period is generally three years, with relative total shareholder return measured for the one, two and three-year periods creating effectively a “nested” 1-year, 2-year, and 3-year plan to support rapid and sustained shareholder value creation.
Vesting period				3 years
Number of trading days to calculate average closing stock price				20 days
Weighted average grant date fair value | $ / shares				$ 4.98	$ 0
Restricted Stock Units, Settled in Cash
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation, maximum grant value | $				$ 0	$ 0
Stock-based compensation arrangements, liability, noncurrent | $				$ 100,000	$ 100,000
President and Chief Executive Officer
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Future stock-based compensation expense | $	$ 4,600,000
Future stock-based compensation expense, period of recognition	3 years
President and Chief Executive Officer | Time-Based Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized (in shares)	423,400
Weighted average grant date fair value | $ / shares	$ 5.17
President and Chief Executive Officer | Performance-Based Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized (in shares)	423,400
Weighted average grant date fair value | $ / shares	$ 5.68
President and Chief Executive Officer | Maximum | Performance-Based Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized (in shares)	635,100
TimkenSteel 2014 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of additional shares authorized (in shares)			0
TimkenSteel 2014 Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized (in shares)			11,050,000
Aggregate share limit ratio			2.50
TimkenSteel 2014 Plan | Current Holders of Timken Equity Awards at Time of Spinoff | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized (in shares)			3,000,000
TimkenSteel 2020 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Aggregate share limit ratio		1
Shares available for grant (in shares)		2,000,000		2,200,000
TimkenSteel 2020 Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized (in shares)		2,000,000
TimkenSteel 2020 Plan | Non-employee Director | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation, maximum grant value | $		$ 500,000

Stock-Based Compensation - Assu

Stock-Based Compensation - Assumptions Used in Calculating Fair Value of Options (Details) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Weighted-average fair value per option (in USD per share)	$ 2.23	$ 5.54	$ 7.46
Risk-free interest rate	0.96%	2.63%	2.77%
Dividend yield	0.00%	0.00%	0.00%
Expected stock volatility	42.67%	41.36%	41.67%
Expected life - years	6 years	6 years	6 years

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Option Activity (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)$ / sharesshares
Number of Shares
Beginning balance (in shares) | shares	2,641,570
Granted (in shares) | shares	511,020
Vested (in shares) | shares	0
Canceled, forfeited or expired (in shares) | shares	(221,525)
Ending balance (in shares) | shares	2,931,065
Options expected to vest, number of shares (in shares) | shares	641,392
Options exercisable, number of shares (in shares) | shares	2,289,673
Weighted Average Exercise Price
Beginning balance (in USD per share) | $ / shares	$ 20.64
Granted (in USD per share) | $ / shares	5.26
Exercised (in USD per share) | $ / shares	0
Canceled, forfeited or expired (in USD per share) | $ / shares	12.08
Ending balance (in USD per share) | $ / shares	18.61
Options expected to vest, weighted average exercise price (in USD per share) | $ / shares	8.21
Options exercisable, weighted average exercise price (in USD per share) | $ / shares	$ 21.52
Additional Information
Outstanding, weighted average remaining contractual term	5 years 2 months 12 days
Options expected to vest, weighted average remaining contractual term	8 years 8 months 12 days
Options exercisable, weighted average remaining contractual term	4 years 2 months 12 days
Outstanding, aggregate intrinsic value | $	$ 0
Options expected to vest, aggregate intrinsic value | $	0
Options exercisable, aggregate intrinsic value | $	$ 0

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Time-Based Restricted Stock Unit Activity (Details) - Time-Based Restricted Stock Units	12 Months Ended
	Dec. 31, 2020$ / sharesshares
Number of Shares
Beginning balance (in shares) | shares	1,103,487
Granted (in shares) | shares	931,244
Vested (in shares) | shares	(548,301)
Canceled, forfeited or expired (in shares) | shares	(114,104)
Ending balance (in shares) | shares	1,372,326
Weighted Average Grant Date Fair Value
Beginning balance (in USD per share) | $ / shares	$ 11.89
Granted (in USD per share) | $ / shares	4.24
Vested (in USD per share) | $ / shares	10.55
Canceled, forfeited or expired (in USD per share) | $ / shares	7.23
Ending balance (in USD per share) | $ / shares	$ 7.62

Stock-Based Compensation - Sc_2

Stock-Based Compensation - Schedule of Performance-Based Restricted Stock Unit Activity (Details) - Performance-Based Restricted Stock Units	12 Months Ended
	Dec. 31, 2020$ / sharesshares
Number of Shares
Beginning balance (in shares) | shares	0
Granted (in shares) | shares	182,180
Canceled, forfeited or expired (in shares) | shares	(6,216)
Ending balance (in shares) | shares	175,964
Weighted Average Grant Date Fair Value
Beginning balance (in USD per share) | $ / shares	$ 0
Granted (in USD per share) | $ / shares	4.98
Canceled, forfeited or expired (in USD per share) | $ / shares	4.97
Ending balance (in USD per share) | $ / shares	$ 4.98

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Loss) - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 563.1	$ 612.9	$ 616.7
Other comprehensive income before reclassifications, before income tax	1.4	0.5
Amounts reclassified from accumulated other comprehensive income (loss), before income tax	(5.6)	(2.4)
Amounts deferred to accumulated other comprehensive income (loss), before income tax		72.2
Income tax	(0.1)	(16.7)	(0.1)
Other comprehensive income (loss), net of tax	(4.3)	53.6	(1.3)
Ending balance	507.5	563.1	612.9
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(6.8)	(7.3)
Other comprehensive income before reclassifications, before income tax	1.4	0.5
Amounts reclassified from accumulated other comprehensive income (loss), before income tax	0	0
Amounts deferred to accumulated other comprehensive income (loss), before income tax		0
Income tax	0	0
Other comprehensive income (loss), net of tax	1.4	0.5
Ending balance	(5.4)	(6.8)	(7.3)
Pension and Postretirement Liability Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	51.5	(1.6)
Other comprehensive income before reclassifications, before income tax	0	0
Amounts reclassified from accumulated other comprehensive income (loss), before income tax	(5.6)	(2.4)
Amounts deferred to accumulated other comprehensive income (loss), before income tax		72.2
Income tax	(0.1)	(16.7)
Other comprehensive income (loss), net of tax	(5.7)	53.1
Ending balance	45.8	51.5	(1.6)
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	44.7	(8.9)	(7.6)
Other comprehensive income (loss), net of tax	(4.3)	53.6	(1.3)
Ending balance	$ 40.4	$ 44.7	$ (8.9)

Contingencies - Narrative (Deta

Contingencies - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Loss Contingency Accrual Disclosures [Abstract]
Contingency reserves	$ 1	$ 1.5

Relationships with The Timken_2

Relationships with The Timken Company and Related Entities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Related Party Transactions [Abstract]
Related party sales of product	$ 23.4	$ 26.1	$ 43.2
Related party sales of product as a percent of sales	2.80%	2.20%	2.70%

Subsequent Events - Narrative (

Subsequent Events - Narrative (Details) - Subsequent Event - Harrison Facility $ in Millions	Feb. 16, 2021USD ($)Employee
Canton, Ohio
Subsequent Event [Line Items]
Expected number of positions to be eliminated | Employee	100
Melt and Cast Related Assets | Minimum
Subsequent Event [Line Items]
Non-cash charges related to write down of assets	$ 8
Melt and Cast Related Assets | Maximum
Subsequent Event [Line Items]
Non-cash charges related to write down of assets	$ 10

Selected Quarterly Financial _3

Selected Quarterly Financial Data (Unaudited) - Schedule of Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 211.2	$ 205.9	$ 154	$ 259.7	$ 226.9	$ 274.2	$ 336.7	$ 371	$ 830.7	$ 1,208.8	$ 1,610.6
Gross profit	14.2	(2.4)	(4)	7.8	(18)	(2.6)	14.8	28.4	15.6	22.6	126.6
Net income (loss)	$ (12.8)	$ (13.9)	$ (15.3)	$ (19.9)	$ (84.6)	$ (17)	$ (11.9)	$ 3.5	$ (61.9)	$ (110)	$ (10)
Per Share Data:
Basic earnings (loss) per share	$ (0.28)	$ (0.31)	$ (0.34)	$ (0.44)	$ (1.89)	$ (0.38)	$ (0.27)	$ 0.08	$ (1.38)	$ (2.46)	$ (0.22)
Diluted earnings (loss) per share	$ (0.28)	$ (0.31)	$ (0.34)	$ (0.44)	$ (1.89)	$ (0.38)	$ (0.27)	$ 0.08	$ (1.38)	$ (2.46)	$ (0.22)

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Allowance for Uncollectible Accounts
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	$ 1.5	$ 1.7	$ 1.4
Charged to Costs and Expenses			0.3
Deductions	(0.2)	(0.2)
Balance at End of Period	1.3	1.5	1.7
Allowance for Inventory Reserves
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	10.7	6.1	8.9
Charged to Costs and Expenses	4.1	9	1.6
Deductions	(0.9)	(4.4)	(4.4)
Balance at End of Period	13.9	10.7	6.1
Valuation Allowance on Deferred Tax Assets
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	34.9	43.7	36.6
Charged to Costs and Expenses	12.4		7.1
Charged to Other Accounts	1.4	16.7
Deductions	(1)	(25.5)
Balance at End of Period	$ 47.7	$ 34.9	$ 43.7