| Cover Cover | Aug. 03, 2020 |
| Document Information [Line Items] | |
| Document Type | 8-K |
| Document Period End Date | Aug. 3, 2020 |
| Entity Registrant Name | Kennametal Inc. |
| Entity Incorporation, State or Country Code | PA |
| Entity File Number | 1-5318 |
| Entity Tax Identification Number | 25-0900168 |
| Entity Address, Address Line One | 525 William Penn Place |
| Entity Address, Address Line Two | Suite 3300 |
| Entity Address, City or Town | Pittsburgh, |
| Entity Address, State or Province | PA |
| Entity Address, Postal Zip Code | 15219 |
| City Area Code | 412 |
| Local Phone Number | 248-8000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0000055242 |
| Document Fiscal Year Focus | 2020 |
| Document Fiscal Period Focus | FY |
| Amendment Flag | false |
| Capital Stock, Par Value $1.25 Per Share | NEW YORK STOCK EXCHANGE, INC. | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Capital Stock, par value $1.25 per share |
| Trading Symbol | KMT |
| Security Exchange Name | NYSE |
| Preferred Stock Purchase Rights | NEW YORK STOCK EXCHANGE, INC. | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Preferred Stock Purchase Rights |
| No Trading Symbol Flag | true |
| Security Exchange Name | NYSE |
