Statement of Changes in Beneficial Ownership (4)

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	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response... 0.5
	Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

1. Name and Address of Reporting Person * RINN RUSSELL B	2. Issuer Name and Ticker or Trading Symbol STEEL DYNAMICS INC [ STLD ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director                      _____ 10% Owner __ X __ Officer (give title below)      _____ Other (specify below) Executive Vice President
(Last)          (First)          (Middle) 7575 W. JEFFERSON BLVD.	3. Date of Earliest Transaction (MM/DD/YYYY) 3/10/2015
(Street) FORT WAYNE, IN 46804 (City)        (State)        (Zip)	4. If Amendment, Date Original Filed (MM/DD/YYYY)	6. Individual or Joint/Group Filing (Check Applicable Line) _ X _ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security (Instr. 3)	2. Trans. Date	2A. Deemed Execution Date, if any	3. Trans. 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	3/10/2015		A		28992   (1)	A	$0	90465	D
Common Stock	3/10/2015		F		11882   (2)	D	$17.88	78583	D

Table II - Derivative Securities Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities)
1. Title of Derivate Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	4. Trans. 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		7. Title and Amount of Securities Underlying Derivative Security (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

Explanation of Responses:
( 1)	Acquisition from Issuer: Shares awarded under Long-Term Incentive Program adopted by Compensation Committee composed of three or more independent non-employee directors pursuant to the Company's Amended and Restated 2006 Equity Incentive Plan approved by Compensation Committee and Stockholders and exempt from Section 16(b) of Exchange Act pursuant to Rule 16b-3(d).
( 2)	Disposition to Issuer: Shares withheld by Issuer in payment of reporting person's withholding tax liability in connection with such person's receipt or vesting of an equity security, and either approved in advance by Compensation Committee or mandated by the express terms of the Plan, and exempt from Section 16(b) of Exchange Act in accordance with Exchange Act Rule 16b-3(e).

Reporting Owners
Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
RINN RUSSELL B 7575 W. JEFFERSON BLVD. FORT WAYNE, IN 46804			Executive Vice President

Signatures
Russell B. Rinn		3/11/2015
** Signature of Reporting Person		Date

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
*	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).
Note:	File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
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