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

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1. Name and Address of Reporting Person * ONEX CORP   2. Issuer Name and Ticker or Trading Symbol TMS International Corp. [TMS] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director __X__ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 161 BAY STREET,  3. Date of Earliest Transaction (Month/Day/Year) 04/19/2011 (Street) TORONTO, A6 M5J 2S1 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) ___ Form filed by One Reporting Person _X_ 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

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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
Class A Preferred Stock (3) (4)	$ 13 (1)	04/19/2011		C			19,390.274	(1)	(1)	Class B Common Stock	20,721,000 (1)	$ 0	0	D
Class B Common Stock (3) (4)	(2)	04/19/2011		C		20,721,000		04/19/2011	(2)	Class A Common Stock	20,721,000	(2)	24,743,138	D
Class B Common Stock (3) (4)	(2)	04/19/2011		S			1,839,239	04/19/2011	(2)	Class A Common Stock	1,839,239	$ 12.155	22,903,899	D
Class A Preferred Stock (3) (4)	$ 13 (1)	04/19/2011		C			11,404.4659	(1)	(1)	Class B Common Stock	12,187,139 (1)	$ 0	0	D
Class B Common Stock (5)	(2)	04/19/2011		C		12,187,139		04/19/2011	(2)	Class A Common Stock	12,187,139	(2)	14,552,755	D
Class B Common Stock (5)	(2)	04/19/2011		S			1,081,755	04/19/2011	(2)	Class A Common Stock	1,081,755	$ 12.155	13,471,020	D
Class A Preferred Stock (6)	$ 13 (1)	04/19/2011		C			95.28	(1)	(1)	Class B Common Stock	101,818 (1)	$ 0	0	D
Class B Common Stock (6)	(2)	04/19/2011		C		101,818		04/19/2011	(2)	Class A Common Stock	101,818	(2)	121,582	D
Class B Common Stock (7)	(2)	04/19/2011		S			9,038	04/19/2011	(2)	Class A Common Stock	9,038	$ 12.155	112,544	D
Class A Preferred Stock (7)	$ 13 (1)	04/19/2011		C			459.726	(1)	(1)	Class B Common Stock	491,276 (1)	$ 0	0	D
Class B Common Stock (7)	(2)	04/19/2011		C		491,276		04/19/2011	(2)	Class A Common Stock	491,276	(2)	586,637	D
Class B Common Stock (7)	(2)	04/19/2011		S			43,607	04/19/2011	(2)	Class A Common Stock	43,607	$ 12.155	543,030	D
Class A Preferred Stock (8)	$ 13 (1)	04/19/2011		C			223.3841	(1)	(1)	Class B Common Stock	238,714 (1)	$ 0	0	D
Class B Common Stock (8)	(2)	04/19/2011		C		238,714		04/19/2011	(2)	Class A Common Stock	238,714	(2)	285,051	D
Class B Common Stock (8)	(2)	04/19/2011		S			21,189	04/19/2011	(2)	Class A Common Stock	21,189	$ 12.155	263,862	D
Class A Preferred Stock (9) (10)	$ 13 (1)	04/19/2011		C			2,621.8027	(1)	(1)	Class B Common Stock	2,801,733 (1)	$ 0	0	D
Class B Common Stock (9) (10)	(2)	04/19/2011		C		2,801,733		04/19/2011	(2)	Class A Common Stock	2,801,733	(2)	3,345,575	D
Class A Preferred Stock	$ 13 (1)	04/19/2011		C			19,850	(1)	(1)	Class B Common Stock	21,212,276 (1)	$ 0	0	I	See footnote (11)
Class B Common Stock	(2)	04/19/2011		C		21,212,276		04/19/2011	(2)	Class A Common Stock	21,212,276	(2)	25,329,775	I	See footnote (11)
Class B Common Stock	(2)	04/19/2011		S			1,882,846	04/19/2011	(2)	Class A Common Stock	1,882,846	$ 12.155	23,446,929	I	See footnote (11)

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
ONEX CORP 161 BAY STREET TORONTO, A6 M5J 2S1		X
SCHWARTZ GERALD W C/O ONEX CORPORATION 161 BAY STREET TORONTO, A6 M5J 2S1		X
Tube City EI II Ltd. C/O ONEX CORPORATION 161 BAY STREET TORONTO, A6 M5J 2S1		X
ONEX PARTNERS II L P C/O ONEX INVESTMENT CORPORATION 712 FIFTH AVENUE NEW YORK, NY 10019		X

Signatures

/s/ Donald Lewtas, attorney-in-fact for Onex Corporation		04/21/2011
**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)	Each share of Class A Preferred Stock was convertible into a number of shares of Class B Common Stock determined by dividing the liquidation preference of such share of Class A Preferred Stock, including accrued but unpaid dividends, at the time of conversion by the conversion price. Concurrently with the initial public offering of the Issuer's Class A Common Stock, each share of Class A Preferred Stock converted into the number of shares of Class B Common Stock on the basis of a conversion price equal to 13.00 per share, the public offering price per share of Class A Common Stock in the offering. The Class A Preferred Stock has no expiration date.
(2)	Shares of Class B Common Stock are convertible on a one-for-one basis at any time, at the option of the holder, into shares of Class A Common Stock and are automatically convertible on a one-for-one basis into shares of Class A Common Stock upon a sale or other disposition to any person other than (i) a person who obtained Class B Common Stock through a direct issuance by the Issuer or (ii) Onex Corporation, Onex Partners II LP or any controlled affiliate of Onex Corporation or Onex Partners II LP. The Class B Common Stock has no expiration date.
(3)	All of the shares owned by Onex Corporation are reported as beneficially owned by each of Onex Corporation and Gerald Schwartz, notwithstanding the fact that Mr. Schwartz has a pecuniary interest in less than 100% of such shares. Mr. Schwartz disclaims beneficial ownership of these securities except to the extent of its or his pecuniary interest therein, and the inclusion of such shares in this report shall not be deemed an admission of beneficial ownership of all of the reported shares for purposes of Section 16 or for any other purpose.
(4)	Onex Corporation may be deemed to own beneficially the shares of Class B Common Stock and Class A Preferred Stock held directly by it and by (a) Onex Partners II LP, through Onex Corporation's ownership of all of the common stock of Onex Partners GP Inc., the general partner of Onex Partners II GP LP, the general partner of Onex Partners II LP, (b) Onex Partners II GP LP, through Onex Corporation's ownership of all of the common stock of Onex Partners GP Inc., the general partner of Onex Partners II GP LP, (c) Onex US Principals LP, through Onex Corporation's ownership of all of the equity of Onex American Holdings II LLC, which owns all of the equity of Onex American Holdings GP LLC, the general partner of Onex US Principals LP, and (d) Tube City EI II Ltd., through Onex Corporation's ownership of all of the common stock of Tube City EI II Ltd. Onex Corporation disclaims beneficial ownership of these securities except to the extent of its direct ownership.
(5)	Represents shares directly owned by Onex Partners II LP. All of the shares owned by Onex Partners II LP are reported as beneficially owned by each of Onex Partners II LP, Onex Corporation and Gerald Schwartz, notwithstanding the fact that each of Onex Corporation and Mr. Schwartz has a pecuniary interest in less than 100% of such shares. Each of Onex Corporation and Mr. Schwartz disclaims beneficial ownership of these securities except to the extent of its or his pecuniary interest therein, and the inclusion of such shares in this report shall not be deemed an admission of beneficial ownership of all of the reported shares for purposes of Section 16 or for any other purpose.
(6)	Represents shares directly owned by Onex Partners II GP LP. All of the shares owned by Onex Partners II GP LP are reported as beneficially owned by each of Onex Partners II GP LP, Onex Corporation and Gerald Schwartz, notwithstanding the fact that each of Onex Corporation and Mr. Schwartz has a pecuniary interest in less than 100% of such shares. Each of Onex Corporation and Mr. Schwartz disclaims beneficial ownership of these securities except to the extent of its or his pecuniary interest therein, and the inclusion of such shares in this report shall not be deemed an admission of beneficial ownership of all of the reported shares for purposes of Section 16 or for any other purpose.
(7)	Represents shares directly owned by 1597257 Ontario Inc. All of the shares owned by 1597257 Ontario Inc. are reported as beneficially owned by each of 1597257 Ontario Inc. and Gerald Schwartz, notwithstanding the fact that each Mr. Schwartz has a pecuniary interest in less than 100% of such shares. Mr. Schwartz disclaims beneficial ownership of these securities except to the extent of his pecuniary interest therein, and the inclusion of such shares in this report shall not be deemed an admission of beneficial ownership of all of the reported shares for purposes of Section 16 or for any other purpose.
(8)	Represents shares directly owned by Onex US Principals LP. All of the shares owned by Onex US Principals LP are reported as beneficially owned by each of Onex US Principals LP, Onex Corporation and Gerald Schwartz, notwithstanding the fact that each of Onex Corporation and Mr. Schwartz has a pecuniary interest in less than 100% of such shares. Each of Onex Corporation and Mr. Schwartz disclaims beneficial ownership of these securities except to the extent of its or his pecuniary interest therein, and the inclusion of such shares in this report shall not be deemed an admission of beneficial ownership of all of the reported shares for purposes of Section 16 or for any other purpose.
(9)	Represents shares directly owned by Tube City EI II Ltd. All of the shares owned by Tube City EI II Ltd. are reported as beneficially owned by each of Tube City EI II Ltd., Onex Corporation and Gerald Schwartz, notwithstanding the fact that Mr. Schwartz has a pecuniary interest in less than 100% of such shares. Each of Onex Corporation and Mr. Schwartz disclaims beneficial ownership of these securities except to the extent of its or his pecuniary interest therein, and the inclusion of such shares in this report shall not be deemed an admission of beneficial ownership of all of the reported shares for purposes of Section 16 or for any other purpose.
(10)	The following people have options to purchase shares of the issuer held by Tube City EI II Ltd.: Gerald Schwartz, Ewout Heersink, Mark Hilson, Andrew Sheiner, Donald Lewtas, Nigel Wright, Chris Govan, Timothy Duncanson, Andrea Daly, Christine Donaldson, David J. Mansell, David R. Hirsch, Kosty Gilis, Andrew Lapham, Scott Mather, and Manish Srivastava.
(11)	Mr. Gerald W. Schwartz, the Chairman, President and Chief Executive Officer of Onex Corporation, owns shares representing a majority of the voting rights of the shares of Onex Corporation. The interests of Onex Corporation are described in footnotes 4 through 10. Mr. Schwartz disclaims beneficial ownership in these securities, and the inclusion of such shares in this report shall not be deemed an admission of beneficial ownership of all of the reported shares for purposes of Section 16 or for any other purpose.
Remarks: **Additional Reporting Person Signatures**  /s/ Donald Lewtas, attorney-in-fact for Gerald W. Schwartz. *Power of Attorney incorporated by reference to the Amendment to Form 4 to Dura Automotive Systems, Inc. filed with the Securities and Exchange Commission by Gerald W. Schwartz on September 10, 1996.*; /s/ Joel I. Greenberg, attorney-in-fact for Onex Partners II LP, Onex Partners II GP LP and Onex US Principals LP; /s/ Donald Lewtas, attorney-in-fact for 1597257 Ontario Inc. and Tube City EI II Ltd.

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