Metallus (MTUS) 10-Q 7 Nov 24 2024 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2024	Oct. 31, 2024
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2024
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q3
Trading Symbol	MTUS
Title of 12(b) Security	Common shares
Security Exchange Name	NYSE
Entity Registrant Name	METALLUS INC.
Entity Central Index Key	0001598428
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		42,494,328
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Document Quarterly 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

Consolidated Statements of Oper

Consolidated Statements of Operations (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Income Statement [Abstract]
Net sales	$ 227.2	$ 354.2	$ 843.5	$ 1,034.3
Cost of products sold	215.1	303.2	756.7	889.2
Gross Profit	12.1	51	86.8	145.1
Selling, general and administrative expenses	22.5	20.5	67.3	61.9
Loss (gain) on sale or disposal of assets, net	0.1	(0.3)	0.4	(2.8)
Interest (income) expense, net	(2.4)	(1.8)	(7.6)	(5)
Loss on extinguishment of debt	0	0	0	11.4
Other (income) expense, net	(1)	(2)	(2.3)	(13.1)
Income (Loss) Before Income Taxes	(7.1)	34.6	29	92.7
Provision (benefit) for income taxes	(1.2)	9.8	6.3	24.6
Net Income (Loss)	$ (5.9)	$ 24.8	$ 22.7	$ 68.1
Per Share Data:
Basic earnings (loss) per share	$ (0.13)	$ 0.56	$ 0.52	$ 1.55
Diluted earnings (loss) per share	$ (0.13)	$ 0.51	$ 0.49	$ 1.43

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Net Income (Loss)	$ (5.9)	$ 24.8	$ 22.7	$ 68.1
Other comprehensive income (loss), net of benefit (provision) for income taxes of $(0.1) million and $0.2 million for the three months ended September 30, 2024 and 2023, and net of benefit (provision) for incomes taxes of $(0.1) million and none for the nine months ended September 30, 2024 and 2023
Foreign currency translation adjustments	0.2	(0.7)	(0.3)	(0.5)
Pension and postretirement liability adjustments	(1.4)	(1.1)	(3.7)	(2.5)
Other comprehensive income (loss), net of tax	(1.2)	(1.8)	(4)	(3)
Comprehensive Income (Loss), net of tax	$ (7.1)	$ 23	$ 18.7	$ 65.1

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Loss) (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Other comprehensive income (loss), tax	$ (0.1)	$ 0.2	$ (0.1)	$ 0

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Current Assets
Cash and cash equivalents	$ 254.6	$ 280.6
Accounts receivable, net of allowances (2024 - $1.5 million; 2023 - $2.0 million)	105.1	113.2
Inventories, net	218	228
Deferred charges and prepaid expenses	17.8	10.3
Other current assets	6.5	24.7
Total Current Assets	602	656.8
Property, plant and equipment, net	496.3	492.5
Operating lease right-of-use assets	11.6	11.4
Pension assets	6.9	9.9
Intangible assets, net	4	2.7
Other non-current assets	12.6	2
Total Assets	1,133.4	1,175.3
Current Liabilities
Accounts payable	113.3	133.3
Salaries, wages and benefits	19.9	26.8
Accrued pension and postretirement costs	17.7	43.5
Current operating lease liabilities	5.1	5
Current convertible notes, net	13.2	13.2
Government funding liabilities	45.5	0
Other current liabilities	13.5	26.6
Total Current Liabilities	228.2	248.4
Non-Current Liabilities
Credit Agreement	0	0
Non-current operating lease liabilities	6.5	6.4
Accrued pension and postretirement costs	157.2	160.5
Deferred income taxes	15.1	15
Other non-current liabilities	13.7	13.4
Total Liabilities	420.7	443.7
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 2024 - 48.2 million shares and 2023 - 47.1 million shares	0	0
Additional paid-in capital	840.4	844.2
Retained deficit	(31)	(53.7)
Treasury shares - 2024 - 5.7 million; 2023 - 4.0 million	(105.1)	(71.3)
Accumulated other comprehensive income (loss)	8.4	12.4
Total Shareholders' Equity	712.7	731.6
Total Liabilities and Shareholders’ Equity	$ 1,133.4	$ 1,175.3

Consolidated Balance Sheets (_2

Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Allowances for accounts receivable	$ 1.5	$ 2
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)	48,200,000	47,100,000
Treasury shares	5,700,000	4,000,000

Consolidated Statements of Shar

Consolidated Statements of Shareholder's Equity (Unaudited) - USD ($) $ in Millions	Total	Common Shares	Additional Paid-in Capital	Retained Earnings (Deficit)	Treasury Shares	Accumulated Other Comprehensive Income (Loss)
Beginning balance at Dec. 31, 2022	$ 686.5		$ 847	$ (123.1)	$ (52.1)	$ 14.7
Beginning balance (in shares) at Dec. 31, 2022		44,064,891
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	14.4			14.4
Other comprehensive income (loss)	(0.6)					(0.6)
Stock-based compensation expense	2.6		2.6
Stock option activity	1.3		1.3
Stock option activity (in shares)		101,130
Purchase of treasury shares, including excise tax	(9.4)				(9.4)
Purchase of treasury shares, including excise tax (in Shares)		(514,086)
Issuance of treasury shares			(11.4)		11.4
Issuance of treasury shares (in shares)		555,062
Shares surrendered for taxes	(3.4)				(3.4)
Shares surrendered for taxes (in shares)		(176,720)
Ending balance at Mar. 31, 2023	691.4		839.5	(108.7)	(53.5)	14.1
Ending balance (in shares) at Mar. 31, 2023		44,030,277
Beginning balance at Dec. 31, 2022	686.5		847	(123.1)	(52.1)	14.7
Beginning balance (in shares) at Dec. 31, 2022		44,064,891
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	68.1
Other comprehensive income (loss)	(3)
Ending balance at Sep. 30, 2023	730.3		842.2	(55)	(68.6)	11.7
Ending balance (in shares) at Sep. 30, 2023		43,248,998
Beginning balance at Mar. 31, 2023	691.4		839.5	(108.7)	(53.5)	14.1
Beginning balance (in shares) at Mar. 31, 2023		44,030,277
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	28.9			28.9
Other comprehensive income (loss)	(0.6)					(0.6)
Stock-based compensation expense	2.9		2.9
Stock option activity	0.6		0.6
Stock option activity (in shares)		76,030
Purchase of treasury shares, including excise tax	(11.4)				(11.4)
Purchase of treasury shares, including excise tax (in Shares)		(650,271)
Issuance of treasury shares			(1.8)		1.8
Issuance of treasury shares (in shares)		29,356
Ending balance at Jun. 30, 2023	711.8		841.2	(79.8)	(63.1)	13.5
Ending balance (in shares) at Jun. 30, 2023		43,485,392
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	24.8			24.8
Other comprehensive income (loss)	(1.8)					(1.8)
Stock-based compensation expense	3		3
Stock option activity	0.5		0.5
Stock option activity (in shares)		61,075
Purchase of treasury shares, including excise tax	(8)		(0.3)		(7.7)
Purchase of treasury shares, including excise tax (in Shares)		(352,860)
Issuance of treasury shares			(2.2)		2.2
Issuance of treasury shares (in shares)		56,131
Shares surrendered for taxes (in shares)		(740)
Ending balance at Sep. 30, 2023	730.3		842.2	(55)	(68.6)	11.7
Ending balance (in shares) at Sep. 30, 2023		43,248,998
Beginning balance at Dec. 31, 2023	731.6		844.2	(53.7)	(71.3)	12.4
Beginning balance (in shares) at Dec. 31, 2023		43,136,311
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	24			24
Other comprehensive income (loss)	(1.1)					(1.1)
Stock-based compensation expense	3.5		3.5
Stock option activity	1.1		1.1
Stock option activity (in shares)		104,360
Purchase of treasury shares, including excise tax	(4.4)				(4.4)
Purchase of treasury shares, including excise tax (in Shares)		(211,571)
Issuance of treasury shares			(13.8)		13.8
Issuance of treasury shares (in shares)		1,707,603
Shares surrendered for taxes	(15.4)				(15.4)
Shares surrendered for taxes (in shares)		(739,352)
Ending balance at Mar. 31, 2024	739.3		835	(29.7)	(77.3)	11.3
Ending balance (in shares) at Mar. 31, 2024		43,997,621
Beginning balance at Dec. 31, 2023	731.6		844.2	(53.7)	(71.3)	12.4
Beginning balance (in shares) at Dec. 31, 2023		43,136,311
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	22.7
Other comprehensive income (loss)	(4)
Ending balance at Sep. 30, 2024	712.7		840.4	(31)	(105.1)	8.4
Ending balance (in shares) at Sep. 30, 2024		42,494,100
Beginning balance at Mar. 31, 2024	739.3		835	(29.7)	(77.3)	11.3
Beginning balance (in shares) at Mar. 31, 2024		43,997,621
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	4.6			4.6
Other comprehensive income (loss)	(1.7)					(1.7)
Stock-based compensation expense	3.5		3.5
Stock option activity	0.2		0.2
Stock option activity (in shares)		21,954
Purchase of treasury shares, including excise tax	(9.6)				(9.6)
Purchase of treasury shares, including excise tax (in Shares)		(439,031)
Issuance of treasury shares			(1.5)		1.5
Issuance of treasury shares (in shares)		59,179
Shares surrendered for taxes (in shares)		(3,518)
Ending balance at Jun. 30, 2024	736.3		837.2	(25.1)	(85.4)	9.6
Ending balance (in shares) at Jun. 30, 2024		43,636,205
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	(5.9)			(5.9)
Other comprehensive income (loss)	(1.2)					(1.2)
Stock-based compensation expense	3.5		3.5
Stock option activity	0.1		0.1
Stock option activity (in shares)		7,968
Purchase of treasury shares, including excise tax	(20.1)				(20.1)
Purchase of treasury shares, including excise tax (in Shares)		(1,159,488)
Issuance of treasury shares			(0.4)		0.4
Issuance of treasury shares (in shares)		13,348
Shares surrendered for taxes (in shares)		(3,933)
Ending balance at Sep. 30, 2024	$ 712.7		$ 840.4	$ (31)	$ (105.1)	$ 8.4
Ending balance (in shares) at Sep. 30, 2024		42,494,100

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Operating Activities
Net Income (Loss)	$ 22.7	$ 68.1
Adjustments to reconcile net income (loss) to net cash provided (used) by operating activities:
Depreciation and amortization	40.4	42.8
Amortization of deferred financing fees	0.4	0.4
Loss on extinguishment of debt	0	11.4
Loss (gain) on sale or disposal of assets, net	0.4	(2.8)
Deferred income taxes	0	0.7
Stock-based compensation expense	10.5	8.5
Pension and postretirement (benefit) expense, net	5.1	6.4
Changes in operating assets and liabilities:
Accounts receivable, net	7.5	(56.1)
Inventories, net	9.2	(62.7)
Accounts payable	(16.4)	34.1
Other accrued expenses	(19.9)	(9.7)
Pension and postretirement contributions and payments	(38)	(2.4)
Deferred charges and prepaid expenses	(7.5)	(5)
Other, net	12	17.5
Net Cash Provided (Used) by Operating Activities	26.4	51.2
Investing Activities
Capital expenditures	(49.1)	(36.2)
Proceeds from government funding	45.5	0
Proceeds from disposals of property, plant and equipment	0	1.7
Net Cash Provided (Used) by Investing Activities	(3.6)	(34.5)
Financing Activities
Purchase of treasury shares	(34.1)	(28.5)
Proceeds from exercise of stock options	1.4	2.4
Shares surrendered for employee taxes on stock compensation	(15.5)	(3.4)
Repayments on convertible notes	0	(18.7)
Net Cash Provided (Used) by Financing Activities	(48.2)	(48.2)
Increase (Decrease) in Cash, Cash Equivalents, and Restricted Cash	(25.4)	(31.5)
Cash, cash equivalents, and restricted cash at beginning of period	281.3	257.8
Cash, Cash Equivalents, and Restricted Cash at End of Period	$ 255.9	$ 226.3

Consolidated Statements of Ca_2

Consolidated Statements of Cash Flows (Unaudited) (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2024	Sep. 30, 2023
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	$ 254.6	$ 225.4
Restricted cash reported in other current assets	1.3	0.9
Total cash, cash equivalents, and restricted cash shown in the Consolidated Statements of Cash Flows	$ 255.9	$ 226.3

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ (5.9)	$ 4.6	$ 24	$ 24.8	$ 28.9	$ 14.4	$ 22.7	$ 68.1

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Sep. 30, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Note 1 - Basis of Presentation The accompanying unaudited Consolidated Financial Statements have been prepared by Metallus Inc. (the “Company” or “Metallus”) in accordance with generally accepted accounting principles in the United States (“U.S. GAAP”) for interim financial information. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) and disclosures considered necessary for a fair presentation have been included. For further information, refer to Metallus' audited Consolidated Financial Statements and Notes included in its Annual Report on Form 10-K for the year ended December 31, 2023 .

Recent Accounting Pronouncement

Recent Accounting Pronouncements	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Recent Accounting Pronouncements	Note 2 - Recent Accounting Pronouncements In November 2021, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2021-10, "Government Assistance (Topic 832), Disclosures by Business Entities about Government Assistance", which requires business entities to provide disclosures on material government assistance transactions for annual reporting periods. The disclosures include information around (1) the nature of the assistance, (2) the related accounting policies used to account for government assistance, (3) the effect of government assistance on the entity’s financial statements, and (4) any significant terms and conditions of the agreements, including commitments and contingencies. The Company prospectively applied the guidance in conjunction with the agreement with United States entered into during the first quarter of 2024. In the three and nine months ended September 30, 2024, the Company received $ 35.5 million and $ 45.5 million, respectively, in funding related to this program and recorded the funding as a current liability on the Consolidated Balance Sheets and as investing within the Consolidated Cash Flows. There was $ 5.8 million in capital spending in the third quarter of 2024 related to assets associated with government-funded projects. The Company will apply the guidance within "International Accounting Standards ("IAS") 20 - Accounting for Government Grants and Disclosure of Government Assistance" and will record the funding received as a reduction to property, plant and equipment at the completion of the project, as the primary conditions for receipt of these funds are to build-out new assets to support increased artillery shell production for the United States Army. In October 2024, the Company received an additional $ 7.0 million in government funding. There are no other current ASUs issued, but not adopted, that are expected to have a material impact on the Company.

Revenue Recognition

Revenue Recognition	9 Months Ended
	Sep. 30, 2024
Revenue from Contract with Customer [Abstract]
Revenue Recognition	Note 3 - Revenue Recognition The following table provides the major sources of revenue by end-market sector for the three and nine months ended September 30, 2024 and 2023: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Industrial $ 91.4 $ 143.0 $ 313.3 $ 415.3 Automotive 104.9 140.1 350.1 404.8 Aerospace & Defense (1) 12.3 30.7 102.3 70.9 Energy 14.5 35.6 63.4 127.7 Other (2) 4.1 4.8 14.4 15.6 Total Net Sales $ 227.2 $ 354.2 $ 843.5 $ 1,034.3 (1) “Aerospace & Defense” sales by end-market were previously included in "Industrial" and have been broken out separately for all periods . (2) “Other” sales by end-market sector relates to the Company’s scrap sales. The following table provides the major sources of revenue by product type for the three and nine months ended September 30, 2024 and 2023: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Bar $ 126.3 $ 240.9 $ 500.3 $ 712.8 Tube 27.6 43.3 110.4 127.5 Manufactured components 69.2 65.2 218.4 178.4 Other (3) 4.1 4.8 14.4 15.6 Total Net Sales $ 227.2 $ 354.2 $ 843.5 $ 1,034.3 (3) “Other” sales by product type relates to the Company’s scrap sales. Contract liabilities are recognized when the Company has received consideration from a customer to transfer goods at a future point in time. Contract liabilities are primarily related to deferred revenue resulting from any cash payments received in advance from customers and are included in other current liabilities on the Consolidated Balance Sheets. There were no contract liabilities as of September 30, 2024 and $ 0.7 million as of September 30, 2023.

Other (Income) Expense, Net

Other (Income) Expense, Net	9 Months Ended
	Sep. 30, 2024
Other Income and Expenses [Abstract]
Other (Income) Expense, Net	Note 4 – Other (Income) Expense, net The following table provides the components of other (income) expense, net for the three and nine months ended September 30, 2024 and 2023: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Pension and postretirement non-service benefit (income) loss $ ( 1.3 ) $ ( 1.2 ) $ ( 4.1 ) $ ( 3.7 ) Loss (gain) from remeasurement of benefit plans — ( 1.0 ) 1.8 1.7 Insurance recoveries — — — ( 11.3 ) Foreign currency exchange (gain) loss 0.3 — — ( 0.1 ) Miscellaneous (income) expense — 0.2 — 0.3 Total other (income) expense, net $ ( 1.0 ) $ ( 2.0 ) $ ( 2.3 ) $ ( 13.1 ) 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 Company's Bargaining Unit Pension Plan ("Bargaining Plan"), the Supplemental Pension Plan ("Supplemental Plan") and the recently terminated Retirement Plan ("Salaried Plan") each have a provision that permits employees to elect to receive their pension benefits in a lump sum upon retirement. In the first quarter of 2024, the cumulative cost of all lump sum payments was expected 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 the first quarter of 2024 and recorded a loss of $ 0.8 million. In the second quarter of 2024, the Company entered into an agreement to purchase a group annuity contract from The Prudential Insurance Company of America (“Prudential”) in connection with the annuitization of the Salaried Plan. The Company remeasured the Salaried Plan upon annuitization on May 15, 2024. A loss of $ 1.0 million from the remeasurement of the Salaried Plan was recognized for the three months ended June 30, 2024. The loss was primarily due to investment losses on plan assets of $ 1.8 million partially offset by a decrease in the liability due to an increase in the discount rate of $ 0.7 million. In addition, the three months ended June 30, 2024 included a $ 0.1 million gain as a result of the completion of the Salaried Plan annuitization. A gain of $ 1.0 million from the remeasurement of the Salaried Plan was recognized for the three months ended September 30, 2023. The gain for the three months ended September 30, 2023 was due to a $ 6.5 million decrease in the liability mainly driven by an increase in the discount rate, partially offset by $ 5.5 million of investment losses on plan assets. For the nine months ended September 30, 2023 , the loss of $ 1.7 million was primarily related to investment losses on plan assets of $ 5.6 million and lump sum basis losses of $ 1.3 million, partially offset by a decrease in the pension liability of $ 5.2 million due to an increase in the discount rate. For more details on the aforementioned remeasurements, refer to “Note 9 - Retirement and Postretirement Plans.” During 2023, the Company recognized insurance recoveries of $ 31.3 million related to the 2022 Faircrest melt shop unplanned downtime. In the first quarter of 2023, the Company recognized recoveries of $ 9.8 million, of which $ 0.8 million was received during the first quarter and $ 9.0 million was received in the second quarter of 2023. In the second quarter of 2023, a $ 1.5 million insurance recovery was received, and the remaining $ 20.0 million was received in the first quarter of 2024. The 2022 insurance claims were closed in the first quarter of 2024. For further information related to previous insurance recoveries, refer to "Note 7 - Other (Income) Expense, net" in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023 .

Income Tax Provision

Income Tax Provision	9 Months Ended
	Sep. 30, 2024
Income Tax Disclosure [Abstract]
Income Tax Provision	Note 5 - Income Tax Provision Metallus’ provision for income taxes in interim periods is computed by applying the appropriate estimated annual effective tax rates to income or loss before income taxes for the period. In addition, non-recurring or discrete items, including interest on prior-year tax liabilities, are recorded during the periods in which they occur. Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Provision (benefit) for incomes taxes $ ( 1.2 ) $ 9.8 $ 6.3 $ 24.6 Effective tax rate 16.9 % 28.3 % 21.7 % 26.5 % Income tax expense for the three months ended September 30, 2024 was calculated using forecasted multi-jurisdictional annual effective tax rates to determine a blended annual effective tax rate. The effective tax rate for the three and nine months ended September 30, 2024 was 16.9 % % and 21.7 % , respectively, compared to a rate of 28.3 % and 26.5 % for the prior year. The decrease in the effective tax rate is primarily related to lower income before income taxes for the three and nine months ended September 30, 2024. In addition to lower income before income taxes, the decrease for the nine months ended September 30, 2024 compared to the nine months ended September 30, 2023 is also impacted by the deductibility of the loss on extinguishment of debt on the Convertible Senior Notes due 2025 and a state net operating loss discrete adjustment that both impacted 2023. For the nine months ended September 30, 2024 , Metallus made $ 21.5 million in U.S. federal tax payments, $ 6.1 million in state and local tax payments, and $ 0.2 million in foreign tax payments. For the nine months ended September 30, 2023 , Metallus made $ 17.0 million in U.S. federal payments, $ 3.4 million in state and local tax payments, and $ 1.2 million in foreign tax payments.

Earnings (Loss) Per Share

Earnings (Loss) Per Share	9 Months Ended
	Sep. 30, 2024
Earnings Per Share [Abstract]
Earnings (Loss) Per Share	Note 6 - Earnings (Loss) Per Share Basic earnings (loss) per share is computed based upon the weighted average number of common shares outstanding. Diluted earnings (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 earnings (loss) per share. Under the if-converted method, the Company adjusts net earnings to add back interest expense (including amortization of debt issuance costs) 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 shares are excluded from the denominator in calculating both basic and diluted earnings (loss) per share. Equity-based Awards Common share equivalents for shares issuable for equity-based awards amounted to 2.4 million shares for the three months ended September 30, 2024. For the three months ended September 30, 2024, common share equivalents for shares issuable for equity-based awards were excluded from the computation of diluted earnings (loss) per share, because the effect of their inclusion would have been anti-dilutive. Common share equivalents for shares issuable for equity-based awards amounted to 2.6 million shares for the nine months ended September 30, 2024. For the nine months ended September 30, 2024, 0.6 million shares were excluded from the computation of diluted earnings (loss) per share, primarily related to options with exercise prices above the average market price of our common shares (i.e., “underwater” options), because the effect of their inclusion would have been anti-dilutive. The difference between the remaining 2.0 million shares assumed issued and the 0.9 million shares assumed purchased with potential proceeds for the nine months ended September 30, 2024 were included in the denominator of the diluted earnings (loss) per share calculation. Common share equivalents for shares issuable for equity-based awards amounted to 3.4 million shares for the three and nine months ended September 30, 2023. For the three and nine months ended September 30, 2023 , 0.3 million shares and 0.7 million shares, respectively, were excluded from the computation of diluted earnings (loss) per share, primarily related to options with exercise prices above the average market price of our common shares (i.e., “underwater” options), because the effect of their inclusion would have been anti-dilutive . The difference between the remaining 3.1 million shares and 2.7 million shares assumed issued and the 1.0 million shares and 0.7 million shares assumed purchased with potential proceeds for the three and nine months ended September 30, 2023, respectively, were included in the denominator of the diluted earnings (loss) per share calculation. Convertible Notes Common share equivalents for shares issuable upon the conversion of outstanding Convertible Notes were excluded in the computation of diluted earnings (loss) per share for the three months ended September 30, 2024 as these shares would be anti-dilutive. Common share equivalents for shares issuable upon the conversion of outstanding Convertible Notes were included in the computation of diluted earnings (loss) per share for the nine months ended September 30, 2024 as these shares would be dilutive. The reduction in the dilutive effect on convertible notes is attributable to the repurchase of outstanding Convertible Notes that occurred in the first quarter of 2023. For additional details regarding the Convertible Notes please refer to “Note 14 - Financing Arrangements” in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023. The following table sets forth the reconciliation of the numerator and the denominator of basic and diluted earnings (loss) per share for the three and nine months ended September 30, 2024 and 2023: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Numerator: Net income (loss), basic $ ( 5.9 ) $ 24.8 $ 22.7 $ 68.1 Add convertible notes interest — 0.2 0.6 0.8 Net income (loss), diluted $ ( 5.9 ) $ 25.0 $ 23.3 $ 68.9 Denominator: Weighted average shares outstanding, basic 43.1 44.1 43.4 44.0 Dilutive effect of stock-based awards — 2.1 1.1 2.0 Dilutive effect of convertible notes — 1.7 1.7 2.0 Weighted average shares outstanding, diluted 43.1 47.9 46.2 48.0 Basic earnings (loss) per share $ ( 0.13 ) $ 0.56 $ 0.52 $ 1.55 Diluted earnings (loss) per share $ ( 0.13 ) $ 0.51 $ 0.49 $ 1.43

Inventories

Inventories	9 Months Ended
	Sep. 30, 2024
Inventory Disclosure [Abstract]
Inventories	Note 7 - Inventories The components of inventories, net of reserves as of September 30, 2024 and December 31, 2023 were as follows: September 30, December 31, Manufacturing supplies $ 57.9 $ 51.5 Raw materials 13.7 17.5 Work in process 108.4 109.6 Finished products 38.7 50.1 Gross inventory 218.7 228.7 Allowance for inventory reserves ( 0.7 ) ( 0.7 ) Total inventories, net $ 218.0 $ 228.0

Financing Arrangements

Financing Arrangements	9 Months Ended
	Sep. 30, 2024
Debt Disclosure [Abstract]
Financing Arrangements	Note 8 - Financing Arrangements For a detailed discussion of the Company's long-term debt and credit arrangements, refer to “Note 14 - Financing Arrangements” in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023. The following table summarizes the current and non-current debt as of September 30, 2024 and December 31, 2023: September 30, December 31, Credit Agreement $ — $ — Convertible Senior Notes due 2025 13.2 13.2 Total debt $ 13.2 $ 13.2 Less current portion of debt 13.2 13.2 Total non-current portion of debt $ — $ — Amended Credit Agreement On September 30, 2022, the Company, as borrower, and certain domestic subsidiaries of the Company, as subsidiary guarantors (the “Subsidiary Guarantors”), entered into a Fourth Amended and Restated Credit Agreement (the “Amended Credit Agreement”), with JPMorgan Chase Bank, N.A., as administrative agent (the “Administrative Agent”), and the lenders party thereto (collectively, the “Lenders”), which further amended and restated the Company’s existing secured Third Amended and Restated Credit Agreement, dated as of October 15, 2019. As of September 30, 2024, the amount available under the Amended Credit Agreement was $ 242.2 million, reflective of the Company’s asset borrowing base with no outstanding borrowings. Additionally, the Company is in compliance with all covenants outlined in the Amended Credit Agreement. Convertible Senior Notes due 2025 The principal amount of the Convertible Senior Notes due 2025 upon issuance was $ 46.0 million. Transaction costs related to the Convertible Senior Notes due 2025 incurred upon issuance were $ 1.5 million. These costs are amortized to interest expense over the term of the notes. The Convertible Senior Notes due 2025 mature on December 1, 2025. The Convertible Senior Notes due 2025 are convertible at the option of holders in certain circumstances and during certain periods into the Company’s common shares, cash, or a combination thereof, at the Company’s election. The Indenture for the Convertible Senior Notes due 2025 provides that notes will become convertible during a quarter when the share price for 20 trading days during the final 30 trading days of the immediately preceding quarter was greater than 130 % of the conversion price. This criterion was met during the third quarter of 2024 and as such the notes can be converted at the option of the holders beginning October 1 through December 31, 2024. Whether the notes will be convertible following such period will depend on if this criterion, or another conversion condition, is met in the future. As such, the Convertible Senior Notes due 2025 are classified as a current liability in the Consolidated Balance Sheets as of September 30, 2024. This criterion was also met as of December 31, 2023. To date, no holders have elected to convert their notes during any optional conversion periods. For details regarding all conversion mechanics and methods of settlement, refer to the Indenture for the Convertible Senior Notes due 2025 filed as an exhibit to a Form 8-K on December 15, 2020 and incorporated by reference in our most recent 10-K filing. In the first quarter of 2023, the Company repurchased a total of $ 7.5 million aggregate principal amount of its Convertible Senior Notes due 2025. Total cash paid to noteholders was $ 18.7 million. A loss on extinguishment of debt of $ 11.4 million was recognized, including a charge of $ 0.2 million for unamortized debt issuance costs related to the portion of debt extinguished, as well as the related transaction costs. The components of the Convertible Senior Notes due 2025 as of September 30, 2024 and December 31, 2023 were as follows: September 30, December 31, Principal $ 13.3 $ 13.3 Less: Debt issuance costs, net of amortization ( 0.1 ) ( 0.1 ) Convertible Senior Notes due 2025, net $ 13.2 $ 13.2 The following table sets forth interest expense recognized specifically related to the Convertible Notes: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Contractual interest expense $ 0.2 $ 0.2 $ 0.6 $ 0.7 Amortization of debt issuance costs — — — 0.1 Total $ 0.2 $ 0.2 $ 0.6 $ 0.8 The total cash interest paid for the nine months ended September 30, 2024 and 2023 wa s $ 1.3 million, respectively. Fair Value Measurement The fair value of the Convertible Senior Notes due 2025 was approximately $ 19.9 million as of September 30, 2024.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 a valuation model primarily using observable market inputs and requires a recurring fair value measurement on a quarterly basis. Metallus’ 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 September 30, 2024. Interest (Income) Expense, net The following table provides the components of interest (income) expense, net for the three and nine months ended September 30, 2024 and 2023: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Interest expense $ 0.7 $ 0.6 $ 2.0 $ 1.9 Interest income ( 3.1 ) ( 2.4 ) ( 9.6 ) ( 6.9 ) Interest (income) expense, net $ ( 2.4 ) $ ( 1.8 ) $ ( 7.6 ) $ ( 5.0 ) Interest income primarily relates to interest earned on cash invested in a money market fund and deposits with financial institutions. As of September 30, 2024 , the carrying value of the Company's money market investment was $ 125.9 million, which approximates the fair value. The Company had $ 96.2 million in cash invested in a money market fund as of September 30, 2023. The money market fund is a cash equivalent and is included in cash and cash equivalents on the Consolidated Balance Sheets. The fund consists of highly liquid investments with an average maturity of three months or less and falls within Level 1 of the fair value hierarchy as defined by applicable accounting guidance. Additionally, as of September 30, 2024 and 2023 , the Company has $ 124.1 and $ 118.5 million, respectively, of cash held in other accounts which generate interest income at a rate similar to the money market fund. Treasury Shares On December 20, 2021 Metallus announced that its Board of Directors authorized a share repurchase program under which the Company may repurchase up to $ 50.0 million of its outstanding common shares. On November 2, 2022, the Board of Directors authorized an additional $ 75.0 million towards its share repurchase program and on May 6, 2024 the Board of Directors authorized an additional $ 100.0 million. The share repurchase program is intended to return capital to shareholders while also offsetting dilution from annual equity compensation awards. The share repurchase program does not require the Company to acquire any dollar amount or number of shares and may be modified, suspended, extended or terminated by the Company at any time without prior notice. These authorizations reflect the continued confidence of the Board and senior leadership in the Company’s ability to generate sustainable through-cycle profitability while maintaining a strong balance sheet and cash flow. For the three months ended September 30, 2024 , the Company repurchased approximately 1.2 million common shares in the open market at an aggregate cost of $ 20.1 million, which equates to an average repurchase price of $ 17.29 per share. For the nine months ended September 30, 2024 , the Company repurchased approximately 1.8 million common shares in the open market at an aggregate cost of $ 34.1 million, which equates to an average repurchase price of $ 18.82 per share. As of September 30, 2024 , the Company had a balance of $ 106.3 million remaining on its authorized share repurchase program. For the three months ended September 30, 2023, the Company repurchased approximately 0.4 million common shares in the open market at an aggregate cost of $ 7.7 million, which equates to an average repurchase price of $ 21.82 per share. For the nine months ended September 30, 2023, the Company repurchased approximately 1.5 million common shares in the open market at an aggregate cost of $ 28.5 million, which equates to an average repurchase price of $ 18.81 per share.

Retirement and Postretirement P

Retirement and Postretirement Plans	9 Months Ended
	Sep. 30, 2024
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Retirement and Postretirement Plans	Note 9 - Retirement and Postretirement Plans Plan Amendments and Updates Bargaining Plan On October 29, 2021, the United Steelworkers ("USW") Local 1123 voted to ratify a new four-year contract (the “Contract”). The Contract, which is in effect until September 27, 2025 , resulted in several changes to the Bargaining Plan including but not limited to closing the plan to new entrants effective January 1, 2022. For a detailed discussion of the Company's Bargaining Plan changes, refer to “Note 15 - Retirement and Postretirement Plans” in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023. In the nine months ended September 30, 2024, the Company contributed a total of $ 37.5 million in pension contributions, most of which related to the Bargaining Plan. In October 2024, the Company contributed an additional $ 5.3 million to the Bargaining Plan, resulting in total 2024 pension contributions of $ 42.8 million. Required future pension contribution timing and amounts are subject to significant change based on future investment performance, Company estimates and actuarial assumptions, as well as current funding laws. Salaried Plan During the fourth quarter of 2021, termination of the Salaried Plan was approved by the Company's Board of Directors. Participants were notified in January 20 22 and the plan was terminated effective March 31, 2022 , subject to regulatory approval which was received in the fourth quarter of 2023. On May 15, 2024, the Company entered into an agreement to purchase a group annuity contract from Prudential in connection with the annuitization of the Salaried Plan. The Salaried Plan annuitization settled approximately $ 121 million of the Company’s remaining U.S. pension obligations. Prudential began future benefit payments under the group annuity contract starting August 1, 2024 for all remaining participants in the Salaried Plan. Benefits payable to Salaried Plan participants were not reduced as a result of the annuitization. The group annuity contract was purchased using existing assets of the Salaried Plan and requires no cash contribution from the Company. At the date of the annuitization of the Salaried Plan, the Company transferred the Salaried Plan assets and liabilities to Prudential and recorded a non-cash loss of approximately $ 1.0 million. Pension Net Periodic Benefit Cost (Income) The components of net periodic benefit cost (income) for the three months ended September 30, 2024 were as follows: Pension United States of America United Kingdom Mexico Bargaining Salaried Supplemental Pension Pension Total Postretirement Service cost $ 2.2 $ — $ — $ — $ — $ 2.2 $ 0.1 Interest cost 6.4 — 0.2 0.6 — 7.2 1.1 Expected return on plan assets ( 7.0 ) — — ( 0.7 ) — ( 7.7 ) ( 0.7 ) Amortization of prior service cost 0.3 — — — — 0.3 ( 1.5 ) Net remeasurement losses (gains) — — — — — — — Net Periodic Benefit Cost (Income) $ 1.9 $ — $ 0.2 $ ( 0.1 ) $ — $ 2.0 $ ( 1.0 ) The components of net periodic benefit cost (income) for the three months ended September 30, 2023 were as follows: Pension United States of America United Kingdom Mexico Bargaining Salaried Supplemental Pension Pension Total Postretirement Service cost $ 2.4 $ 0.2 $ — $ — $ — $ 2.6 $ 0.2 Interest cost 6.5 1.6 0.2 0.5 — 8.8 1.2 Expected return on plan assets ( 6.7 ) ( 1.8 ) — ( 0.6 ) — ( 9.1 ) ( 0.9 ) Amortization of prior service cost 0.3 — — — — 0.3 ( 1.5 ) Net remeasurement losses (gains) — ( 1.0 ) — — — ( 1.0 ) — Net Periodic Benefit Cost (Income) $ 2.5 $ ( 1.0 ) $ 0.2 $ ( 0.1 ) $ — $ 1.6 $ ( 1.0 ) The components of net periodic benefit cost (income) for the nine months ended September 30, 2024 were as follows: Pension United States of America United Kingdom Mexico Bargaining Salaried Supplemental Pension Pension Total Postretirement Service cost $ 6.6 $ 0.3 $ — $ — $ — $ 6.9 $ 0.3 Interest cost 19.2 2.5 0.6 1.8 — 24.1 3.3 Expected return on plan assets ( 21.0 ) ( 2.7 ) — ( 2.1 ) — ( 25.8 ) ( 2.1 ) Amortization of prior service cost 0.9 — — — — 0.9 ( 4.5 ) Net remeasurement losses (gains) — 1.8 — — — 1.8 — Net Periodic Benefit Cost (Income) $ 5.7 $ 1.9 $ 0.6 $ ( 0.3 ) $ — $ 7.9 $ ( 3.0 ) The components of net periodic benefit cost (income) for the nine months ended September 30, 2023 were as follows: Pension United States of America United Kingdom Mexico Bargaining Salaried Supplemental Pension Pension Total Postretirement Service cost $ 7.2 $ 0.6 $ — $ — $ — $ 7.8 $ 0.6 Interest cost 19.5 4.9 0.6 1.5 — 26.5 3.6 Expected return on plan assets ( 20.1 ) ( 5.6 ) — ( 1.8 ) — ( 27.5 ) ( 2.7 ) Amortization of prior service cost 0.9 — — — — 0.9 ( 4.5 ) Net remeasurement losses (gains) — 1.7 — — — 1.7 — Net Periodic Benefit Cost (Income) $ 7.5 $ 1.6 $ 0.6 $ ( 0.3 ) $ — $ 9.4 $ ( 3.0 ) The Bargaining Plan, Supplemental Plan and the recently terminated Salaried Plan have a provision that permits employees to elect to receive their pension benefits in a lump sum upon retirement. The Company's accounting policy is to recognize settlements during the quarter in which it is projected that the costs of all settlements during the year will be greater than the sum of the service cost and interest cost components. In the first quarter of 2024, the cumulative cost of all lump sum payments was expected 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 r emeasurement of its pension obligations and plan assets associated with the Salaried Plan during the first quarter of 2024. On May 1, 2024, in advance of the annuitization of the Salaried plan and upon the election of certain participants, the Company made $ 20.8 million in lump sum payments. The Company remeasured the Salaried Plan ahead of the annuitization on May 15, 2024. In the first quarter of 2023, in anticipation of receiving the regulatory approval to move forward with the plan termination process, the cumulative costs of all lump sum payments and other settlements were projected to exceed this threshold during 2023 for the Salaried Plan. Ultimately, these costs did not exceed this threshold for the Salaried Plan during 2023. The Salaried Plan's pension obligations and plan assets were remeasured during each quarter of 2023.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2024
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	Note 10 – Stock-Based Compensation During the nine months ended September 30, 2024 the Board of Directors granted 427,996 time-based restricted stock units and 205,944 performance-based restricted stock units, which relates to the annual grant to our employees and grants to the Board of Directors. During the nine months ended September 30, 2023 the Board of Directors granted 383,519 time-based restricted stock units and 211,639 performance-based restricted stock units, which relates to the annual grant to our employees and Board of Directors. Time-based restricted stock units are issued with the fair value equal to the closing market price of Metallus 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 occur during the vesting period. The weighted average fair value of the restricted stock units granted during the nine months ended September 30, 2024 was $ 20.66 per share. Performance-based restricted stock units issued in 2024 vest based on achievement of a total shareholder return (“TSR”) metric. The TSR metric is considered a market condition, which requires Metallus 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 under ASC 718 – Stock-based Compensation. 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 the performance-based restricted stock units granted during the nine months ended September 30, 2024 was $ 18.73 per share. In the fourth quarter of 2023, the Board approved and authorized a performance-based Transformation Incentive Grant program (the “Transformation Incentive Grant Program”). Under the Transformation Incentive Grant Program, certain employees were granted performance-based restricted stock unit awards designed to be earned based upon the closing price performance of the Company's common shares during a performance period running from December 1, 2023 through December 31, 2026. Similar to the annual performance-based restricted stock units, the fair value of each share is determined using a Monte Carlo valuation model, a generally accepted lattice pricing model. There were no additional grants under the Transformation Incentive Grant Program during 2024. For further information, refer to Metallus' Stock Based Compensation note included in its Annual Report on Form 10-K for the year ended December 31, 2023. Metallus recognized stock-based compensation expense of $ 3.5 million and $ 10.5 million for the three and nine months ended September 30, 2024 , compared to $ 3.0 million and $ 8.5 million for the three and nine months ended September 30, 2023 . Future stock-based compensation expense related to the unvested portion of all awards is approximately $ 22.3 million . The future expense is expected to be recognized over the remaining vesting periods through 2027.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	9 Months Ended
	Sep. 30, 2024
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income (Loss)	Note 11 - Accumulated Other Comprehensive Income (Loss) Changes in accumulated other comprehensive income (loss) for the nine months ended September 30, 2024 and 2023 by component were as follows: Foreign Currency Pension and Total Balance as of December 31, 2023 $ ( 6.5 ) $ 18.9 $ 12.4 Other comprehensive income (loss) before reclassifications, before income tax ( 0.3 ) — ( 0.3 ) Amounts reclassified from accumulated other comprehensive income (loss), before income tax — ( 3.6 ) ( 3.6 ) Amounts deferred to accumulated other comprehensive income (loss), before income tax — — — Tax effect — ( 0.1 ) ( 0.1 ) Net current period other comprehensive income (loss), net of income taxes ( 0.3 ) ( 3.7 ) ( 4.0 ) Balance as of September 30, 2024 $ ( 6.8 ) $ 15.2 $ 8.4 Foreign Currency Pension and Total Balance as of December 31, 2022 $ ( 6.8 ) $ 21.5 $ 14.7 Other comprehensive income (loss) before reclassifications, before income tax ( 0.5 ) — ( 0.5 ) Amounts reclassified from accumulated other comprehensive income (loss), before income tax — ( 3.7 ) ( 3.7 ) Amounts deferred to accumulated other comprehensive income (loss), before income tax — 1.2 1.2 Tax effect — — — Net current period other comprehensive income (loss), net of income taxes ( 0.5 ) ( 2.5 ) ( 3.0 ) Balance as of September 30, 2023 $ ( 7.3 ) $ 19.0 $ 11.7 The amount reclassified from accumulated other comprehensive income (loss) in the nine months ended September 30, 2024 and 2023 for the pension and postretirement liability adjustment was included in other (income) expense, net in the unaudited Consolidated Statements of Operations.

Contingencies

Contingencies	9 Months Ended
	Sep. 30, 2024
Loss Contingency Accrual, Disclosures [Abstract]
Contingencies	Note 12 – Contingencies Metallus has a number of loss exposures incurred in the ordinary course of business, such as environmental claims, product warranty claims, employee-related matters, and other 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 September 30, 2024 and December 31, 2023, Metallus had a $ 1.3 m illion and a $ 1.1 million contingency reserve, respectively, related to loss exposures incurred in the ordinary course of business.

Revenue Recognition (Tables)

Revenue Recognition (Tables)	9 Months Ended
	Sep. 30, 2024
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following table provides the major sources of revenue by end-market sector for the three and nine months ended September 30, 2024 and 2023: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Industrial $ 91.4 $ 143.0 $ 313.3 $ 415.3 Automotive 104.9 140.1 350.1 404.8 Aerospace & Defense (1) 12.3 30.7 102.3 70.9 Energy 14.5 35.6 63.4 127.7 Other (2) 4.1 4.8 14.4 15.6 Total Net Sales $ 227.2 $ 354.2 $ 843.5 $ 1,034.3 (1) “Aerospace & Defense” sales by end-market were previously included in "Industrial" and have been broken out separately for all periods . (2) “Other” sales by end-market sector relates to the Company’s scrap sales. The following table provides the major sources of revenue by product type for the three and nine months ended September 30, 2024 and 2023: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Bar $ 126.3 $ 240.9 $ 500.3 $ 712.8 Tube 27.6 43.3 110.4 127.5 Manufactured components 69.2 65.2 218.4 178.4 Other (3) 4.1 4.8 14.4 15.6 Total Net Sales $ 227.2 $ 354.2 $ 843.5 $ 1,034.3 (3) “Other” sales by product type relates to the Company’s scrap sales.

Other (Income) Expense, Net (Ta

Other (Income) Expense, Net (Tables)	9 Months Ended
	Sep. 30, 2024
Other Income and Expenses [Abstract]
Schedule of Other (Income) Expense, Net	The following table provides the components of other (income) expense, net for the three and nine months ended September 30, 2024 and 2023: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Pension and postretirement non-service benefit (income) loss $ ( 1.3 ) $ ( 1.2 ) $ ( 4.1 ) $ ( 3.7 ) Loss (gain) from remeasurement of benefit plans — ( 1.0 ) 1.8 1.7 Insurance recoveries — — — ( 11.3 ) Foreign currency exchange (gain) loss 0.3 — — ( 0.1 ) Miscellaneous (income) expense — 0.2 — 0.3 Total other (income) expense, net $ ( 1.0 ) $ ( 2.0 ) $ ( 2.3 ) $ ( 13.1 )

Income Tax Provision (Tables)

Income Tax Provision (Tables)	9 Months Ended
	Sep. 30, 2024
Income Tax Disclosure [Abstract]
Schedule of (Benefit) Provision for Income Taxes	Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Provision (benefit) for incomes taxes $ ( 1.2 ) $ 9.8 $ 6.3 $ 24.6 Effective tax rate 16.9 % 28.3 % 21.7 % 26.5 %

Earnings (Loss) Per Share (Tabl

Earnings (Loss) Per Share (Tables)	9 Months Ended
	Sep. 30, 2024
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 earnings (loss) per share for the three and nine months ended September 30, 2024 and 2023: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Numerator: Net income (loss), basic $ ( 5.9 ) $ 24.8 $ 22.7 $ 68.1 Add convertible notes interest — 0.2 0.6 0.8 Net income (loss), diluted $ ( 5.9 ) $ 25.0 $ 23.3 $ 68.9 Denominator: Weighted average shares outstanding, basic 43.1 44.1 43.4 44.0 Dilutive effect of stock-based awards — 2.1 1.1 2.0 Dilutive effect of convertible notes — 1.7 1.7 2.0 Weighted average shares outstanding, diluted 43.1 47.9 46.2 48.0 Basic earnings (loss) per share $ ( 0.13 ) $ 0.56 $ 0.52 $ 1.55 Diluted earnings (loss) per share $ ( 0.13 ) $ 0.51 $ 0.49 $ 1.43

Inventories (Tables)

Inventories (Tables)	9 Months Ended
	Sep. 30, 2024
Inventory Disclosure [Abstract]
Schedule of Components of Inventory	The components of inventories, net of reserves as of September 30, 2024 and December 31, 2023 were as follows: September 30, December 31, Manufacturing supplies $ 57.9 $ 51.5 Raw materials 13.7 17.5 Work in process 108.4 109.6 Finished products 38.7 50.1 Gross inventory 218.7 228.7 Allowance for inventory reserves ( 0.7 ) ( 0.7 ) Total inventories, net $ 218.0 $ 228.0

Financing Arrangements (Tables)

Financing Arrangements (Tables)	9 Months Ended
	Sep. 30, 2024
Debt Instrument [Line Items]
Summary of Current and Non-current Debt	The following table summarizes the current and non-current debt as of September 30, 2024 and December 31, 2023: September 30, December 31, Credit Agreement $ — $ — Convertible Senior Notes due 2025 13.2 13.2 Total debt $ 13.2 $ 13.2 Less current portion of debt 13.2 13.2 Total non-current portion of debt $ — $ —
Schedule of Interest (income) Expense	The following table provides the components of interest (income) expense, net for the three and nine months ended September 30, 2024 and 2023: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Interest expense $ 0.7 $ 0.6 $ 2.0 $ 1.9 Interest income ( 3.1 ) ( 2.4 ) ( 9.6 ) ( 6.9 ) Interest (income) expense, net $ ( 2.4 ) $ ( 1.8 ) $ ( 7.6 ) $ ( 5.0 )
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 September 30, 2024 and December 31, 2023 were as follows: September 30, December 31, Principal $ 13.3 $ 13.3 Less: Debt issuance costs, net of amortization ( 0.1 ) ( 0.1 ) Convertible Senior Notes due 2025, net $ 13.2 $ 13.2
Convertible Notes
Debt Instrument [Line Items]
Schedule of Interest (income) Expense	The following table sets forth interest expense recognized specifically related to the Convertible Notes: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Contractual interest expense $ 0.2 $ 0.2 $ 0.6 $ 0.7 Amortization of debt issuance costs — — — 0.1 Total $ 0.2 $ 0.2 $ 0.6 $ 0.8

Retirement and Postretirement_2

Retirement and Postretirement Plans (Tables)	9 Months Ended
	Sep. 30, 2024
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Schedule of Defined Benefit Plans Disclosures	The components of net periodic benefit cost (income) for the three months ended September 30, 2024 were as follows: Pension United States of America United Kingdom Mexico Bargaining Salaried Supplemental Pension Pension Total Postretirement Service cost $ 2.2 $ — $ — $ — $ — $ 2.2 $ 0.1 Interest cost 6.4 — 0.2 0.6 — 7.2 1.1 Expected return on plan assets ( 7.0 ) — — ( 0.7 ) — ( 7.7 ) ( 0.7 ) Amortization of prior service cost 0.3 — — — — 0.3 ( 1.5 ) Net remeasurement losses (gains) — — — — — — — Net Periodic Benefit Cost (Income) $ 1.9 $ — $ 0.2 $ ( 0.1 ) $ — $ 2.0 $ ( 1.0 ) The components of net periodic benefit cost (income) for the three months ended September 30, 2023 were as follows: Pension United States of America United Kingdom Mexico Bargaining Salaried Supplemental Pension Pension Total Postretirement Service cost $ 2.4 $ 0.2 $ — $ — $ — $ 2.6 $ 0.2 Interest cost 6.5 1.6 0.2 0.5 — 8.8 1.2 Expected return on plan assets ( 6.7 ) ( 1.8 ) — ( 0.6 ) — ( 9.1 ) ( 0.9 ) Amortization of prior service cost 0.3 — — — — 0.3 ( 1.5 ) Net remeasurement losses (gains) — ( 1.0 ) — — — ( 1.0 ) — Net Periodic Benefit Cost (Income) $ 2.5 $ ( 1.0 ) $ 0.2 $ ( 0.1 ) $ — $ 1.6 $ ( 1.0 ) The components of net periodic benefit cost (income) for the nine months ended September 30, 2024 were as follows: Pension United States of America United Kingdom Mexico Bargaining Salaried Supplemental Pension Pension Total Postretirement Service cost $ 6.6 $ 0.3 $ — $ — $ — $ 6.9 $ 0.3 Interest cost 19.2 2.5 0.6 1.8 — 24.1 3.3 Expected return on plan assets ( 21.0 ) ( 2.7 ) — ( 2.1 ) — ( 25.8 ) ( 2.1 ) Amortization of prior service cost 0.9 — — — — 0.9 ( 4.5 ) Net remeasurement losses (gains) — 1.8 — — — 1.8 — Net Periodic Benefit Cost (Income) $ 5.7 $ 1.9 $ 0.6 $ ( 0.3 ) $ — $ 7.9 $ ( 3.0 ) The components of net periodic benefit cost (income) for the nine months ended September 30, 2023 were as follows: Pension United States of America United Kingdom Mexico Bargaining Salaried Supplemental Pension Pension Total Postretirement Service cost $ 7.2 $ 0.6 $ — $ — $ — $ 7.8 $ 0.6 Interest cost 19.5 4.9 0.6 1.5 — 26.5 3.6 Expected return on plan assets ( 20.1 ) ( 5.6 ) — ( 1.8 ) — ( 27.5 ) ( 2.7 ) Amortization of prior service cost 0.9 — — — — 0.9 ( 4.5 ) Net remeasurement losses (gains) — 1.7 — — — 1.7 — Net Periodic Benefit Cost (Income) $ 7.5 $ 1.6 $ 0.6 $ ( 0.3 ) $ — $ 9.4 $ ( 3.0 )

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 30, 2024
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 nine months ended September 30, 2024 and 2023 by component were as follows: Foreign Currency Pension and Total Balance as of December 31, 2023 $ ( 6.5 ) $ 18.9 $ 12.4 Other comprehensive income (loss) before reclassifications, before income tax ( 0.3 ) — ( 0.3 ) Amounts reclassified from accumulated other comprehensive income (loss), before income tax — ( 3.6 ) ( 3.6 ) Amounts deferred to accumulated other comprehensive income (loss), before income tax — — — Tax effect — ( 0.1 ) ( 0.1 ) Net current period other comprehensive income (loss), net of income taxes ( 0.3 ) ( 3.7 ) ( 4.0 ) Balance as of September 30, 2024 $ ( 6.8 ) $ 15.2 $ 8.4 Foreign Currency Pension and Total Balance as of December 31, 2022 $ ( 6.8 ) $ 21.5 $ 14.7 Other comprehensive income (loss) before reclassifications, before income tax ( 0.5 ) — ( 0.5 ) Amounts reclassified from accumulated other comprehensive income (loss), before income tax — ( 3.7 ) ( 3.7 ) Amounts deferred to accumulated other comprehensive income (loss), before income tax — 1.2 1.2 Tax effect — — — Net current period other comprehensive income (loss), net of income taxes ( 0.5 ) ( 2.5 ) ( 3.0 ) Balance as of September 30, 2023 $ ( 7.3 ) $ 19.0 $ 11.7

Recent Accounting Pronounceme_2

Recent Accounting Pronouncements - Narrative (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended	9 Months Ended
	Oct. 31, 2024	Sep. 30, 2024	Sep. 30, 2024
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Government assistance, liability		$ 35.5	$ 45.5
Government assistance capital fundings		$ 5.8
Subsequent Event
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Government assistance, additional fund received	$ 7

Revenue Recognition (Details)

Revenue Recognition (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Disaggregation of Revenue Line Items
Net sales		$ 227.2	$ 354.2	$ 843.5	$ 1,034.3
Bar
Disaggregation of Revenue Line Items
Net sales		126.3	240.9	500.3	712.8
Tube
Disaggregation of Revenue Line Items
Net sales		27.6	43.3	110.4	127.5
Manufactured Components
Disaggregation of Revenue Line Items
Net sales		69.2	65.2	218.4	178.4
Other
Disaggregation of Revenue Line Items
Net sales	[1]	4.1	4.8	14.4	15.6
Industrial
Disaggregation of Revenue Line Items
Net sales		91.4	143	313.3	415.3
Automotive
Disaggregation of Revenue Line Items
Net sales		104.9	140.1	350.1	404.8
Aerospace and Defense
Disaggregation of Revenue Line Items
Net sales	[2]	12.3	30.7	102.3	70.9
Energy
Disaggregation of Revenue Line Items
Net sales		14.5	35.6	63.4	127.7
Other
Disaggregation of Revenue Line Items
Net sales	[3]	$ 4.1	$ 4.8	$ 14.4	$ 15.6
[1] (3) “Other” sales by product type relates to the Company’s scrap sales. (1) “Aerospace & Defense” sales by end-market were previously included in "Industrial" and have been broken out separately for all periods . (2) “Other” sales by end-market sector relates to the Company’s scrap sales.

Revenue Recognition - Narrative

Revenue Recognition - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2024	Sep. 30, 2023
Revenue from Contract with Customer [Abstract]
Contract liabilities totaled	$ 0	$ 0.7

Disposition of Non-Core Assets

Disposition of Non-Core Assets (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations Line Items
Proceeds from disposals of property, plant and equipment	$ 0	$ 1.7

Other (Income) Expense, Net - S

Other (Income) Expense, Net - Schedule of Other (Income) Expense, Net (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended		12 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Other Income and Expenses [Abstract]
Pension and postretirement non-service benefit (income) loss	$ (1.3)			$ (1.2)			$ (4.1)	$ (3.7)
Loss (gain) from remeasurement of benefit plans	0	$ 1	$ 0.8	(1)			1.8	1.7
Insurance recoveries	0			0	$ (1.5)	$ (9.8)	0	(11.3)	$ (31.3)
Foreign currency exchange (gain) loss	0.3			0			0	(0.1)
Miscellaneous (income) expense	0			0.2			0	0.3
Total other (income) expense, net	$ (1)			$ (2)			$ (2.3)	$ (13.1)

Other (Income) Expense, Net - N

Other (Income) Expense, Net - Narrative (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended		12 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Other Income and Expenses [Abstract]
Loss (gain) from remeasurement of benefit plans	$ 0	$ 1	$ 0.8	$ (1)			$ 1.8	$ 1.7
Decrease in liability				6.5				5.2
Investment losses on plan assets		1.8		5.5				1.7
Investment on plan assets								5.6
Lump sum based loss								1.3
Investment gains on plan assets		0.7
Gain on plan asset annuitization		$ 0.1
Insurance recoveries	$ 0			$ 0	$ 1.5	$ 9.8	$ 0	$ 11.3	$ 31.3
Total recovery			$ 20		$ 9	$ 0.8

Income Tax Provision - Schedule

Income Tax Provision - Schedule of (Benefit) Provision for Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Income Tax Disclosure [Abstract]
Provision (benefit) for income taxes	$ (1.2)	$ 9.8	$ 6.3	$ 24.6
Effective tax rate	16.90%	28.30%	21.70%	26.50%

Income Tax Provision - Narrativ

Income Tax Provision - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Operating Loss Carryforwards [Line Items]
Effective tax rate	16.90%	28.30%	21.70%	26.50%
U.S.
Operating Loss Carryforwards [Line Items]
Income taxes paid			$ 21.5	$ 17
State and Local
Operating Loss Carryforwards [Line Items]
Income taxes paid			6.1	3.4
Foreign
Operating Loss Carryforwards [Line Items]
Income taxes paid			$ 0.2	$ 1.2

Earnings (Loss) Per Share - Add

Earnings (Loss) Per Share - Additional Information (Details) - shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Shares assumed issued		3.1	2	2.7
Shares assumed purchased with potential proceeds		1	0.9	0.7
Underwater Options [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of computation of diluted earnings (loss) per share		0.3	0.6	0.7
Equity-based Awards [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of computation of diluted earnings (loss) per share	2.4	3.4	2.6	3.4

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		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Numerator:
Net income (loss), basic	$ (5.9)	$ 24.8	$ 22.7	$ 68.1
Add convertible notes interest	0	0.2	0.6	0.8
Net income (loss), diluted	$ (5.9)	$ 25	$ 23.3	$ 68.9
Denominator:
Weighted average shares outstanding, basic (in shares)	43.1	44.1	43.4	44
Dilutive effect of stock-based awards (in shares)	0	2.1	1.1	2
Dilutive effect of convertible notes (in shares)	0	1.7	1.7	2
Weighted average shares outstanding, diluted (in shares)	43.1	47.9	46.2	48
Basic earnings (loss) per share	$ (0.13)	$ 0.56	$ 0.52	$ 1.55
Diluted earnings (loss) per share	$ (0.13)	$ 0.51	$ 0.49	$ 1.43

Inventories - Schedule of Inven

Inventories - Schedule of Inventory (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Inventory Disclosure [Abstract]
Manufacturing supplies	$ 57.9	$ 51.5
Raw materials	13.7	17.5
Work in process	108.4	109.6
Finished products	38.7	50.1
Gross inventory	218.7	228.7
Allowance for inventory reserves	(0.7)	(0.7)
Total inventories, net	$ 218	$ 228

Financing Arrangements - Summar

Financing Arrangements - Summary of Current and Non-current Debt (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Total debt	$ 13.2	$ 13.2
Less current portion of debt	13.2	13.2
Total non-current portion of debt	0	0
Credit Agreement
Debt Instrument [Line Items]
Total debt	0	0
Convertible Senior Notes due 2025
Debt Instrument [Line Items]
Total debt	$ 13.2	$ 13.2

Financing Arrangements - Narrat

Financing Arrangements - Narrative (Details) shares in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2024 USD ($) shares	Sep. 30, 2023 USD ($) shares	Mar. 31, 2023 USD ($)	Sep. 30, 2024 USD ($) Days shares	Sep. 30, 2023 USD ($) shares	May 06, 2024 USD ($)	Nov. 02, 2022 USD ($)	Dec. 20, 2021 shares
Debt Instrument [Line Items]
Settled with cash payment				$ 0	$ 18,700,000
Interest paid				1,300,000	1,300,000
Loss on extinguishment of debt	$ 0	$ 0		0	(11,400,000)
Common Stock, Shares outstanding | shares								50
Money market investment carrying value	125,900,000	96,200,000		125,900,000	96,200,000
Cash Held In Other Investments	124,100,000	118,500,000		124,100,000	118,500,000
Average Repurchase price	$ 17.29	$ 21.82		$ 18.82	$ 18.81
Stock Repurchase Program, Amount						$ 100,000,000	$ 75,000,000
Common Shares
Debt Instrument [Line Items]
Stock Repurchased, Shares | shares	1.2	0.4		1.8	1.5
Stock Repurchased, Amount	$ 20,100,000	$ 7,700,000		$ 34,100,000	$ 28,500,000
Stock Repurchase Program, Remaining Amount	106,300,000			106,300,000
Third Amended Credit Facility | Credit Agreement
Debt Instrument [Line Items]
Line of credit facility, tentative future commitment increase	242,200,000			242,200,000
Convertible Senior Notes due 2025
Debt Instrument [Line Items]
Outstanding borrowings	0			0
Transaction costs, debt gross	1,500,000			$ 1,500,000
Terms of conversion				The Convertible Senior Notes due 2025 are convertible at the option of holders in certain circumstances and during certain periods into the Company’s common shares, cash, or a combination thereof, at the Company’s election.
Settled with cash payment			$ 18,700,000
Debt instrument, threshold trading days | Days				20
Debt Instrument, threshold consecutive trading days | Days				30
Debt Instrument, threshold Percentage of stock price conversion				130%
Fair value of convertible notes	19,900,000			$ 19,900,000
Debt Instrument, Face Amount	$ 46,000,000		7,500,000	$ 46,000,000
Loss on extinguishment of debt			11,400,000
Unamortized debt issuance costs			$ 200,000

Financing Arrangements - Schedu

Financing Arrangements - Schedule of Convertible Debt (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Total debt	$ 13.2	$ 13.2
Convertible Senior Notes due 2025
Debt Instrument [Line Items]
Principal	13.3	13.3
Less: Debt issuance costs, net of amortization	(0.1)	(0.1)
Total debt	$ 13.2	$ 13.2

Financing Arrangements - Sche_2

Financing Arrangements - Schedule of Interest Expense (Details) - Convertible Notes - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Debt Instrument [Line Items]
Contractual interest expense	$ 0.2	$ 0.2	$ 0.6	$ 0.7
Amortization of debt issuance costs	0	0	0	0.1
Total	$ 0.2	$ 0.2	$ 0.6	$ 0.8

Financing Arrangements - Sche_3

Financing Arrangements - Schedule of Components of Interest (Income) Expense (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Interest Expense, Operating and Nonoperating [Abstract]
Interest expense	$ 0.7	$ 0.6	$ 2	$ 1.9
Interest income	(3.1)	(2.4)	(9.6)	(6.9)
Interest (income) expense, net	$ (2.4)	$ (1.8)	$ (7.6)	$ (5)

Retirement and Postretirement_3

Retirement and Postretirement Plans - Narrative (Details) - USD ($) $ in Millions		1 Months Ended		3 Months Ended	9 Months Ended
	May 01, 2024	Oct. 31, 2024	Oct. 29, 2021	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2024
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Bargaining Plan's obligations	$ 20.8
Salaried Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan Terminated Effective Date					Mar. 31, 2022
Non cash gain (loss)					$ (1)
Bargaining Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan term of contract			4 years
Defined benefit plan contract expiration date			Sep. 27, 2025
Company contributions to plans					37.5
Bargaining Plan | Forecast [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Anticipated contribution during the year							$ 42.8
Bargaining Plan | Subsequent Event
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Company contributions to plans		$ 5.3
Pension
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Settlement gain				$ 1	(1.8)	$ (1.7)
Pension | Salaried Plan | United States of America
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan settlement					121
Settlement gain				$ 1	$ (1.8)	$ (1.7)

Retirement and Postretirement_4

Retirement and Postretirement Plans - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Pension
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 2.2	$ 2.6	$ 6.9	$ 7.8
Interest cost	7.2	8.8	24.1	26.5
Expected return on plan assets	(7.7)	(9.1)	(25.8)	(27.5)
Amortization of prior service cost	0.3	0.3	0.9	0.9
Net remeasurement losses (gains)		(1)	1.8	1.7
Net Periodic Benefit Cost (Income)	2	1.6	7.9	9.4
Pension | United States of America | Bargaining Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	2.2	2.4	6.6	7.2
Interest cost	6.4	6.5	19.2	19.5
Expected return on plan assets	(7)	(6.7)	(21)	(20.1)
Amortization of prior service cost	0.3	0.3	0.9	0.9
Net Periodic Benefit Cost (Income)	1.9	2.5	5.7	7.5
Pension | United States of America | Salaried Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost		0.2	0.3	0.6
Interest cost		1.6	2.5	4.9
Expected return on plan assets		(1.8)	(2.7)	(5.6)
Net remeasurement losses (gains)		(1)	1.8	1.7
Net Periodic Benefit Cost (Income)		(1)	1.9	1.6
Pension | United States of America | Supplemental Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Interest cost	0.2	0.2	0.6	0.6
Net Periodic Benefit Cost (Income)	0.2	0.2	0.6	0.6
Pension | United Kingdom | Pension Scheme
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Interest cost	0.6	0.5	1.8	1.5
Expected return on plan assets	(0.7)	(0.6)	(2.1)	(1.8)
Net Periodic Benefit Cost (Income)	(0.1)	(0.1)	(0.3)	(0.3)
Postretirement
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	0.1	0.2	0.3	0.6
Interest cost	1.1	1.2	3.3	3.6
Expected return on plan assets	(0.7)	(0.9)	(2.1)	(2.7)
Amortization of prior service cost	(1.5)	(1.5)	(4.5)	(4.5)
Net Periodic Benefit Cost (Income)	$ (1)	$ (1)	$ (3)	$ (3)

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 3.5	$ 3	$ 10.5	$ 8.5
Future stock-based compensation expense			$ 22.3
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares granted			427,996	383,519
Fair value of shares granted			$ 20.66
Performance Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares granted			205,944	211,639
Fair value of shares granted			$ 18.73

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Loss) - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 736.3	$ 739.3	$ 731.6	$ 711.8	$ 691.4	$ 686.5	$ 731.6	$ 686.5
Other comprehensive income (loss) before reclassifications, before income tax							(0.3)	(0.5)
Amounts reclassified from accumulated other comprehensive income (loss), before income tax							(3.6)	(3.7)
Amounts deferred to accumulated other comprehensive income (loss),before income tax							0	1.2
Tax effect	(0.1)			0.2			(0.1)	0
Other comprehensive income (loss), net of tax	(1.2)	(1.7)	(1.1)	(1.8)	(0.6)	(0.6)	(4)	(3)
Ending balance	712.7	736.3	739.3	730.3	711.8	691.4	712.7	730.3
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance			(6.5)			(6.8)	(6.5)	(6.8)
Other comprehensive income (loss) before reclassifications, before income tax							(0.3)	(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	0
Tax effect							0	0
Other comprehensive income (loss), net of tax							(0.3)	(0.5)
Ending balance	(6.8)			(7.3)			(6.8)	(7.3)
Pension and Postretirement Liability Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance			18.9			21.5	18.9	21.5
Other comprehensive income (loss) before reclassifications, before income tax							0	0
Amounts reclassified from accumulated other comprehensive income (loss), before income tax							(3.6)	(3.7)
Amounts deferred to accumulated other comprehensive income (loss),before income tax							0	1.2
Tax effect							(0.1)	0
Other comprehensive income (loss), net of tax							(3.7)	(2.5)
Ending balance	15.2			19			15.2	19
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	9.6	11.3	12.4	13.5	14.1	14.7	12.4	14.7
Other comprehensive income (loss), net of tax	(1.2)	(1.7)	(1.1)	(1.8)	(0.6)	(0.6)
Ending balance	$ 8.4	$ 9.6	$ 11.3	$ 11.7	$ 13.5	$ 14.1	$ 8.4	$ 11.7

Contingencies - Narrative (Deta

Contingencies - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Loss Contingency Accrual, Disclosures [Abstract]
Contingency reserves	$ 1.3	$ 1.1