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( Mark One ) ANNUAL REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington , D.C. 20549 Form 10 - K For the Fiscal Year Ended December 31 , 2020 or TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 Ohio ( State or other jurisdiction of incorporation or organization ) Title of Each Class Common Stock , no par value 6070 Parkland Blvd. , Mayfield Heights , Ohio ( Address of principal executive offices ) For the Transition Period from MATERION CORPORATION ( Exact name of registrant as specified in its charter ) 34-1919973 ( I.R.S. Employer Identification No. ) " to Commission File Number 1-15885 44124 ( Zip Code ) Registrant's telephone number , including area code 216-486-4200 Securities registered pursuant to Section 12 ( b ) of the Act : Trading Symbol ( s ) MTRN Name of Each Exchange on Which Registered New York Stock Exchange Securities registered pursuant to Section 12 ( g ) of the Act : None ( Title of Class ) . Indicate by check mark if the registrant is a well - known seasoned issuer , as defined in Rule 405 of the Securities Act . Yes ý 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 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 such filing requirements for the past 90 days . Yes ý No No No ý 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 ( § 232.405 of this chapter ) during the preceding 12 months ( or for such shorter period that the registrant was required to submit such files ) . Yes ý 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 . Large accelerated filer X Non - accelerated filer Accelerated filer Smaller reporting company Emerging growth company If an emerging growth company , indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13 ( a ) of the Exchange Act . Indicate by check mark whether the registrant has filed a report on and attestation to its management's assessment of the effectiveness of its internal control over financial reporting under Section 404 ( b ) of the Sarbanes - Oxley Act ( 15 U.S.C. 7262 ( b ) ) by the registered public accounting firm that prepared or issued its audit report . X Indicate by check mark whether the registrant is a shell company ( as defined in Rule 12b - 2 of the Act ) . Yes No The aggregate market value of common shares , no par value , held by non - affiliates of the registrant ( based upon the closing sale price on the New York Stock Exchange ) on June 26 , 2020 was $ 1,175,158,375 . As of January 29 , 2021 , there were 20,330,126 common shares , no par value , outstanding . DOCUMENTS INCORPORATED BY REFERENCE Portions of the Proxy Statement for the 2021 Annual Meeting of Shareholders are incorporated by reference into Part III .