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Exhibit 32.1

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 A. M. Castle & Co. (the “Company”) on Form 10-Q for the period ended September 30, 2007 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), Michael H. Goldberg, President and Chief Executive Officer (Principal Executive Officer) and Lawrence A. Boik, Vice President and Chief Financial Officer (Principal Financial Officer) of the Company, respectively, do each hereby certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that to the best of his knowledge:

(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 result of operations of the Company and its subsidiaries.

/s/ Michael H. Goldberg Michael H. Goldberg

President and Chief Executive Officer
(Principal Executive Officer)

November 2, 2007

/s/ Lawrence A. Boik

Lawrence A. Boik

Vice President and Chief Financial Officer
(Principal Financial Officer)

November 2, 2007