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( Mark One ) UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON , D.C. 20549 ANNUAL REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 OR TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 Delaware ( State or other jurisdiction of incorporation or organization ) FORM 10 - K 1735 Market Street , 15th Floor Philadelphia , Pennsylvania ( Address of principal executive offices ) For the fiscal year ended June 30 , 2021 CARPENTER TECHNOLOGY CORPORATION ( Exact name of registrant as specified in its charter ) Securities registered pursuant to Section 12 ( b ) of the Act : Common Stock , $ 5 Par Value Title of each class For the transition period from to Commission File Number 1-5828 610-208-2000 ( Registrant's telephone number , including area code ) CRS Trading Symbol Securities registered pursuant to 12 ( g ) of the Act : None Indicate by check mark if the registrant is a well - known seasoned issuer , as defined in Rule 405 of the Securities Act . Yes No 23-0458500 Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15 ( d ) of the Act . Yes No X ( I.R.S. Employer Identification No. ) 19103 New York Stock Exchange Name of each exchange on which registered ( Zip Code ) Indicate by check mark whether the registrant ( 1 ) has filed all reports required to be filed by Section 13 or 15 ( d ) of the Securities Exchange Act of 1934 during the preceding 12 months ( or for such shorter period that the registrant was required to file such reports ) , and ( 2 ) has been subject to the filing requirements for at least the past 90 days . Yes No Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S - T during the preceding 12 months ( or for such shorter period that the registrant was required to post such files ) Yes > No Indicate by check mark whether the registrant is a large accelerated filer , an accelerated filer , a non - accelerated filer , a smaller reporting company or an emerging growth company . See the definitions of " large accelerated filer , " " accelerated filer , " " smaller reporting company " and " emerging growth company " in Rule 12b - 2 of the Exchange Act .