X0203 3 2010-04-22 0 0000018172 CASTLE A M & CO CAS 0001193398 BIEMER ALBERT J 3400 NORTH WOLF ROAD FRANKLIN PARK IL 60131 0 1 0 0 Vice President, Supply Chain Common Stock 2600 D Restricted Stock Units Common Stock 3700 D Performance Share Units Common Stock 3700 D Employee Stock Options (right to buy) 12.79 2013-03-18 2018-03-17 Common Stock 7300 D Employee Stock Options (right to buy) 5.21 2004-10-23 2013-10-23 Common Stock 4667 D The restricted stock units vest in full on December 31, 2012, provided the reporting person is employed by A. M. Castle & Co. on the vesting date. Each restricted stock unit represents a contingent right to receive one share of common stock of A. M. Castle & Co. (the "Company"). The PSUs will vest on December 31, 2012, if the reporting person remains employed by the Company over the performance period and the Company determines that it acheived certain total shareholder return ("TSR") performance goals. The performance period begins on January 1, 2010 and ends December 31, 2012. Once vested, payout for PSU's can range from 0% to 200% based on the Company's relative TSR over the performance period as compared to a group of peer companies. TSR is measured generally as the increase or decrease in the market value of Company common stock including the reinvestment of dividends. The grant amount of 3,700 PSUs assumes 100% vesting. Since payout for PSUs can range from 0% to 200%, the maximum number of shares that could vest and be distributed is 7,400. Each performance share unit (PSU) represents a contingent right to receive one share of A. M. Castle & Co. common stock. Exhibit List: Exhibit 24 - Power of Attorney Robert J. Perna, Attorney-in-Fact 2010-05-03