============================================================================== SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 ------------ SCHEDULE 13E-3 (Amendment No. 1) Rule 13E-3 Transaction Statement (Pursuant to Section 13(e) of the Securities Exchange Act of 1934) ------------ TRIMAS CORPORATION (Name of Issuer) ------------ MASCOTECH, INC. MASCOTECH ACQUISITION, INC. TRIMAS CORPORATION (Name of Person(s) Filing Statement) ------------ Common Stock, $.01 Par Value (Title of Class of Securities) ------------ 896215100 (CUSIP Number of Class of Securities) ------------ David B. Liner, Esq. Brian P. Campbell MascoTech, Inc. TriMas Corporation 21001 Van Born Road 315 East Eisenhower Parkway Taylor, Michigan 48180 Ann Arbor, Michigan 48108 (313) 274-7405 (313) 747-7025 (Name, Address and Telephone Number of Persons Authorized to Receive Notices and Communications on Behalf of Person(s) Filing Statement) ------------ With Copies to: David W. Ferguson, Esq. Jerome M. Schwartz, Esq. Davis Polk & Wardwell Dickinson, Wright, Moon, Van Dusen & Freeman 450 Lexington Avenue 500 Woodward Avenue, Suite 4000 New York, NY 10017 Detroit, Michigan 48226 (212) 450-4000 (313) 223-3628 ============================================================================== This Amendment No. 1 (this "Amendment") amends and supplements the Rule 13e-3 Transaction Statement on Schedule 13E-3 (the "Schedule 13E-3") originally filed on December 17, 1997 by (i) MascoTech, Inc., a Delaware corporation ("Parent"), (ii) MascoTech Acquisition, Inc., a Delaware corporation ("Purchaser") and (iii) TriMas Corporation, a Delaware corporation (the "Company") relating to the offer by Purchaser to purchase all of the issued and outstanding shares (the "Shares") of common stock, $.01 par value per share, of TriMas Corporation, a Delaware corporation, at a price of $34.50 per Share, net to the seller in cash, upon the terms and subject to the conditions set forth in the Offer to Purchase dated December 17, 1997 and in the related Letter of Transmittal. All capitalized terms used in this Amendment without definition have the meanings attributed to them in the Schedule 13E-3. The item of the Schedule 13E-3 set forth below is hereby amended by adding the following: Item 17. Material to be Filed as Exhibits. (g)(3) Complaint filed in Charter Capital Corp. v. Manoogian et al. (Court of Chancery in the State of Delaware in and for New Castle County, filed December 11, 1997).+ (g)(4) Complaint filed in Caruso v. TriMas Corporation et al. (Court of Chancery of the State of Delaware in and for New Castle County, filed December 11, 1997).+ (g)(5) Complaint filed in Barsky v. TriMas Corporation et al. (Court of Chancery of the State of Delaware in and for New Castle County, filed December 11, 1997).+ + Incorporated by reference to Amendment No. 1, filed by Purchaser and Parent on December 22, 1997, to the Tender Offer Statement on Schedule 14D-1 originally filed by Purchaser and Parent on December 17, 1997. SIGNATURE After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this Amendment is true, complete and correct. December 22, 1997 MASCOTECH, INC. By: /s/ David B. Liner ----------------------------- Name: David B. Liner Title: Vice President and Corporate Counsel MASCOTECH ACQUISITION, INC. By: /s/ David B. Liner ----------------------------- Name: David B. Liner Title: Secretary TRIMAS CORPORATION By: /s/ Brian P. Campbell ----------------------------- Name: Brian P. Campbell Title: President