Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the incorporation by reference in this Amendment No. 1 to Registration Statement No. 333-142337 on Form S-3, of our reports dated March 20, 2007, relating to the financial statements and financial statement schedule of A.M. Castle & Co. and subsidiaries, and management’s report on the effectiveness of internal control over financial reporting appearing in the Annual Report on Form 10-K of A.M. Castle & Co. and subsidiaries for the year ended December 31, 2006 and to the reference to us under the heading “Experts” in the Prospectus, which is part of this Registration Statement.

/s/ DELOITTE & TOUCHE LLP

Chicago, Illinois
May 8, 2007