FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL OMB Number: 3235-0287 Expires: January 31, 2005 Estimated average burden hours per response... 0.5

(Print or Type Responses)

1. Name and Address of Reporting Person * Tredwell Daniel P   2. Issuer Name and Ticker or Trading Symbol TRIMAS CORP [TRS] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 177 BROAD STREET, 10TH FLOOR 3. Date of Earliest Transaction (Month/Day/Year) 05/30/2013 (Street) STAMFORD, CT 06901 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 05/30/2013   S   50,000 D $ 32.62 (1) 2,163,170 I See Footnote (2) Common Stock 05/31/2013   S   18,200 D $ 32.57 (3) 2,144,970 I See Footnote (2) Common Stock               3,448 D

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
	Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.		SEC 1474 (9-02)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Tredwell Daniel P 177 BROAD STREET 10TH FLOOR STAMFORD, CT 06901	X

Signatures

/s/ Paula Reno attorney-in-fact		05/31/2013
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	Represents the weighted average sale price of $32.62 rounded to the nearest hundredths. The highest price at which the shares were purchased was $32.91 and the lowest price at which the shares were purchased was $32.50, in each case, rounded to the nearest hundredths. The Reporting Person undertakes that he will provide, upon request by the staff of the U.S. Securities and Exchange Commission, full information regarding the number of securities purchased at each separate price.
(2)	These securities are owned directly by TriMas Investment Fund I, L.L.C. ("TIF I"). The Reporting Person is the Managing Member of Heartland Industrial Associates, L.L.C. ("Heartland"), the General Partner of Heartland Industrial Partners, L.P., which is TIF I's Managing Member. Prior acquisitions and dispositions by Heartland and its affiliated funds of shares of TriMas Corporation common stock were previously reported by Heartland and its affiliated funds, which are no longer subject to Section 16 reporting obligations. The Reporting Person disclaims beneficial ownership (as defined in Rule 16a-1(a)(2)) of these securities except to the extent of his pecuniary interest therein.
(3)	Represents the weighted average sale price of $32.57 rounded to the nearest hundredths. The highest price at which the shares were purchased was $32.75 and the lowest price at which the shares were purchased was $32.50, in each case, rounded to the nearest hundredths. The Reporting Person undertakes that he will provide, upon request by the staff of the U.S. Securities and Exchange Commission, full information regarding the number of securities purchased at each separate price.

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

Potential persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB number.