X0303 4 2011-05-26 0 0000842633 TRIMAS CORP TRS 0001326561 Wathen David M 39400 WOODWARD AVENUE SUITE 130 BLOOMFIELD HILLS 48304 1 1 0 0 President and CEO Common Stock 2011-05-26 4 M 0 133333 1.38 A 371576 D Common Stock 2011-05-26 4 S 0 63411 20.94 D 308165 D Employee Stock Option (right to buy) 1.38 2011-05-26 4 M 0 133333 0 D 2011-01-13 2019-01-13 Common Stock 133333 66667 D The first and second of three installments for options granted January 13, 2009 pursuant to the 2006 Long Term Equity Incentive Plan vested on January 13, 2010 and January 13, 2011 respectively. David M. Wathen and Laurene A. Wathen JT TEN WROS The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $20.88 to $21.25 inclusive. The reporting person undertakes to provide to TriMas Corporation, any security holder of TriMas Corporation, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnote (3) to this Form 4. /s/ Paula Reno attorney-in-fact 2011-05-27