X0303 4 2010-04-22 0 0000018172 CASTLE A M & CO CAS 0001184782 SIMPSON MICHAEL 3400 NORTH WOLF ROAD FRANKLIN PARK IL 60131 1 0 0 0 Common Stock 2010-04-22 4 A 0 3876 0 A 94505 D Common Stock 10546 I See Note Common Stock 22781 I See Note Common Stock 262433 I See Note Common Stock 20992 I See Note Common Stock 157872 I See Note Common Stock 1372.0200 I Through 401(k) Plan Beneficiary under Trust dated 12/07/1949 United States Trust Co., Trustee Beneficiary under Trust dated 7/24/1968 United States Trust Co., Trustee Beneficiary under Trust dated 7/26/1972 United States Trust Co. and Patrick J. Herbert, III, Trustee Beneficiary under Trust dated 12/23/1976 Northern Trust Co., Trustee Beneficiary under Trust dated 12/19/1980 Patrick J. Herbert, III, Trustee Between December 1, 2009 and March 31, 2010 the reporting person's share balance of A. M. Castle & Co. stock under the A. M. Castle & Co. 401(k) plan decreased by 0.3059 shares. The information in this report is based on a plan statement dated as of March 31, 2010. Robert J. Perna, Attorney-in-Fact 2010-04-23