EXHIBIT 23

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the incorporation by reference in the Registration Statement (Nos. 333-18423, 333-88049 and
333-124774) on Form S-8 of Kennametal Inc. of our report dated June 23, 2010, with respect to the statements of net assets available for benefits of the Kennametal Retirement Income Savings Plan as of December 31, 2009 and 2008, and the related statement of changes in net assets available for benefits for the year ended December 31, 2009 and the supplemental schedule of assets (held at end of year) as of December 31, 2009, which report appears in the December 31, 2009 Annual Report on the Form 11-K of the Kennametal Retirement Income Savings Plan.

/s/ Schneider Downs & Co., Inc.  

Schneider Downs & Co., Inc. 

Pittsburgh, Pennsylvania
June 23, 2010