EXHIBIT 32(a)

                         CORE MOLDING TECHNOLOGIES, INC.

                            CERTIFICATION PURSUANT TO
                             18 U.S.C. SECTION 1350,
                             AS ADOPTED PURSUANT TO
                  SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

      In connection with the Quarterly Report of Core Molding Technologies, Inc.
(the "Company") on Form 10-Q for the period ending March 31, 2005 as filed with
the Securities and Exchange Commission on the date hereof (the "Report"), I,
James L. Simonton, President, Chief Executive Officer and Director of the
Company, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to
Section 906 of the Sarbanes-Oxley Act of 2002 that:

      (1)   The Report fully complies with the requirements of section 13(a) or
            15(d) of the Securities Exchange Act of 1934; and

      (2)   The information contained in the Report fairly presents, in all
            material respects, the financial condition and results of operations
            of the Company.

                                   /s/ James L. Simonton
                               -----------------------------------------------
                               James L. Simonton
                               President, Chief Executive Officer and Director
                               May 16, 2005

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