Exhibit 99.1

Steel Dynamics Reports Fourth Quarter 2011 Diluted Earnings Per Share of $0.14

Full-Year 2011 Net Income Increases 98% to $278 Million, Compared to 2010

FORT WAYNE, INDIANA, January 24, 2012 / PRNewswire / Steel Dynamics, Inc. (NASDAQ/GS: STLD) today announced fourth quarter net income of $30 million, or $0.14 per diluted share, on net sales of $1.9 billion. By comparison, prior year fourth quarter net income was $8 million, or $0.04 per diluted share, on net sales of $1.5 billion.  Full-year 2011 net income increased 98% to $278 million, or $1.22 per diluted share, on net sales of $8.0 billion, compared to prior year net income of $141 million, or $0.64 per diluted share, on net sales of $6.3 billion.

“We are pleased with the strong revenue and bottom-line performance in both the quarter and for the year in comparison to prior year results,” said President and Chief Executive Officer Mark Millett.  “We achieved both quarterly and annual organic sales growth of over 20 percent, and nearly doubled our annual pretax earnings in a challenging environment.  Many of our operations achieved notable milestones in 2011:

·                  Our Flat Roll and Engineered Bar Products divisions achieved record annual production and shipping volumes individually, as did our steel operations in total,

·                  Our Engineered Bar Products and Steel of West Virginia steel divisions achieved record annual operating income,

·                  We significantly increased our market share of railroad rail business, shipping 117,000 tons in 2011 (more than double the 55,000 tons shipped during 2010),

·                  Our metals recycling operations achieved record annual ferrous and nonferrous shipping volumes, as we leveraged improved market dynamics through additional retail yards and increased shredder capacity,

·                  We achieved record production of iron units at our Iron Dynamics facility, with the lowest cost structure achieved to date, and

·                  We began operations at three fabrication facilities located strategically in the South and Southwest, providing market expansion.

This solid performance in a difficult economy is driven by our ongoing commitment to provide exceptional value to our customers, while sustaining our innovative, low-cost operating culture.”

Fourth Quarter Review

Fourth quarter volumes increased in each of the company’s operating segments when compared to the prior-year fourth quarter and decreased when compared to the third quarter of 2011.  While the company’s operating income increased 76 percent over prior-year performance, it decreased 24 percent in comparison to the third quarter of 2011.  The decrease in consecutive quarterly operating income was primarily the result of compressed flat roll margins and Iron Dynamics’ planned three week maintenance shutdown, which reduced operating income by $10 million due to associated costs and reduced volume.   Despite increased volumes, earnings from flat roll operations declined 26 percent, as lower selling prices in the first half of the quarter were not matched with corresponding declines in the cost of raw materials, resulting in margin compression.  However, beginning mid-quarter, increases in both order entry and pricing should benefit the first quarter of 2012.

Fourth quarter margins for the combined steel operations expanded in comparison to prior year fourth quarter results, as the average selling price per ton shipped increased $100 per ton to $853, and the average ferrous scrap cost per ton melted increased $68.  In contrast, steel margins compressed in comparison to the third quarter of 2011, as the average selling price per ton shipped decreased $44 per ton across the steel group, and the average ferrous scrap cost per ton melted decreased only $12.

As is typical in the last quarter of the year, metals recycling volumes decreased when compared to the third quarter of 2011, but increases in nonferrous margins more than offset the impact of reduced ferrous and nonferrous shipments.  Operating income for OmniSource was $16 million in the fourth quarter, an increase of $7 million in comparison to prior year, and an increase of $4 million compared to the third quarter of 2011.  Non-cash unrealized hedging losses were $3 million, or approximately $0.01 per diluted share, in the fourth quarter of 2011, as compared to gains of $2 million in the third quarter of 2011.

The impact of losses from the company’s Minnesota operations on fourth quarter 2011 consolidated net income was $10 million, or approximately $0.05 per diluted share.  This compares to losses of $8 million, or approximately $0.03 per diluted share in the third quarter of 2011.  The increased loss was a function of margin compression as product pricing decreased and the cost of raw materials increased quarter over quarter.  Fourth quarter shipments of iron nuggets was 53,000 metric tons, a 62 percent increase over third quarter 2011 levels.

Full-Year Review

Overall 2011 shipping volumes increased in each of the company’s operating segments when compared to prior year, and record volumes were achieved in the steel and metals recycling operations.  2011 net sales of $8.0 billion, increased $1.7 billion, or 27 percent, over 2010 results, and were only 1 percent less than the company’s record net sales achieved in 2008.

The company’s operating income increased 60 percent versus the prior year, driven primarily by significant margin improvement within the steel operations in both flat and long products.  The average annual selling price per ton shipped for the company’s steel operations in 2011 was $897, an increase of $123 per ton compared to 2010.  The 2011 average ferrous scrap cost per ton melted increased $71.

Outlook

As previously reported in early January, the company successfully expanded its existing senior secured credit facility by adding a $275 million term loan facility.  The net proceeds from the term loan were used to repay approximately $278 million, or 40 percent, of the company’s outstanding 73/8 % Senior Notes due November 2012, in accordance with the announced cash tender offer.  During the first quarter of 2012, the company expects to recognize expenses of approximately $10 million (net of interest cost savings) associated with the refinancing, including the tender premium and unamortized financing fee write-offs.  During the remainder of the year beginning in April through maturity in November, the refinancing is expected to result in interest cost savings of approximately $9 million (based on current interest rates).

“Entering the new year,” Millett said, “we are optimistic, despite continued uncertainty within the U.S. and global economies.  We believe there is the possibility for more stability to develop in 2012 as improvements continue in certain market sectors, such as energy, agriculture, automotive, transportation and construction equipment.   If the U.S. economy continues a pattern of slow and steady growth during the year, steel demand should logically follow, given the relatively low levels of inventory across the supply chain.  We remain confident that with our exceptional team, coupled with our superior, low-cost operating culture, we are uniquely prepared to capitalize on the opportunities ahead.”

Summary Fourth Quarter and Full-Year 2011 Operating Segment Information

The following tables highlight operating results for each of the company’s three primary operating segments. References to segment operating income in the following paragraphs exclude profit-sharing costs and amortization pertaining to intangible assets.  (Amounts excluding full year 2010 data are unaudited, and dollar amounts are in thousands, excluding per ton data.)

Steel Operations

This segment includes five electric-arc-furnace steel mills and related steel finishing and processing facilities, including The Techs. The company’s steel operations produce flat-rolled steel, structural steel, merchant bars, special-bar-quality steel, rebar, rail, and specialty shapes.

Metals Recycling and Ferrous Resources

This segment principally includes the company’s metals recycling operations (OmniSource Corporation), a liquid pig iron production facility (Iron Dynamics), and the company’s Minnesota operations, which currently primarily includes an iron nugget manufacturing facility (Mesabi Nugget, which is 81 percent company-owned).

Metals Recycling and Ferrous Resources

Metals Recycling

Steel Fabrication Operations

Steel fabrication operations include New Millennium Building Systems, which fabricates steel joists, trusses, and decking used in the construction of non-residential buildings.  Fourth quarter and annual 2010 operating losses of $13 million and $25 million, respectively, include a $13 million impairment charge.

About Steel Dynamics, Inc.

Steel Dynamics, Inc. is one of the largest domestic steel producers and metals recyclers in the United States based on estimated annual steelmaking and metals recycling capability, with annual sales of $8.0 billion in 2011, 6,500 employees, and manufacturing facilities primarily located throughout the United States (five steel mills, six steel processing facilities, two iron production facilities, over 70 metals recycling locations and six steel fabrication plants).

Forward-Looking Statement

This press release contains some predictive statements about future events, including statements related to conditions in the steel and metallic scrap markets, Steel Dynamics’ revenues, costs of purchased materials, future profitability and earnings, and the operation of new or existing facilities. These statements are intended to be made as “forward-looking,” subject to many risks and uncertainties, within the safe harbor protections of the Private Securities Litigation Reform Act of 1995. These statements speak only as of this date and are based upon information and assumptions, which we consider reasonable as of this date, concerning our businesses and the environments in which they operate. Such predictive statements are not guarantees of future performance, and we undertake no duty to update or revise any such statements. Some factors that could cause such forward-looking statements to turn out differently than anticipated include: the effects of a prolonged or deepening recession on industrial demand; (2) changes in economic conditions, either generally or in any of the steel or scrap-consuming sectors which affect demand for our products, including the strength of the non-residential and residential construction, automotive, appliance, and other steel-consuming industries; (3) fluctuations in the cost of key raw materials (including steel scrap, iron units, and energy costs) and our ability to pass-on any cost increases; (4) the impact of domestic and foreign import price competition; (5) risks and uncertainties involving product and/or technology development; and (6) occurrences of unexpected plant outages or equipment failures.

More specifically, we refer you to SDI’s more detailed explanation of these and other factors and risks that may cause such predictive statements to turn out differently, as set forth in our most recent Annual Report on Form 10-K, in our quarterly reports on Form 10-Q or in other reports which we from time to time file with the Securities and Exchange Commission. These are available publicly on the SEC Web site, www.sec.gov, and on the Steel Dynamics Web site, www.steeldynamics.com.

Conference Call and Webcast

On Wednesday, January 25, 2012, at 10:00 a.m. Eastern time, Steel Dynamics will host a conference call with investors and analysts to discuss the company’s fourth quarter and full-year 2011 results.  We invite you to listen to the live audiocast of the conference call accessible from our website (http://steeldynamics.com) , or via telephone (the conference call number may be obtained on our website).   A replay of the discussion will be available on our website following the conclusion of the conference call.

Contact:  Theresa E. Wagler, Executive Vice President and Chief Financial Officer — +1.260.969.3500

Steel Dynamics, Inc.

CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED)

(in thousands, except per share data)

(Note 1) Excludes the impact of the 4% convertible subordinated notes from net income (numerator) and share equivalents outstanding (denominator) for the three months ended December 31, 2011and 2010, as the impact to diluted earnings per share is anti-dilutive.

Steel Dynamics, Inc.

UNAUDITED SUPPLEMENTAL OPERATING INFORMATION

(dollars in thousands)

*                       Steel Operations include the company’s five steelmaking divisions and The Techs three galvanizing plants.

**                 Metals Recycling and Ferrous Resources Operations include OmniSource; Iron Dynamics (all shipments are internal); and Mesabi Nugget (all shipments, which began in 2010, have been internal).

***           Steel Fabrication Operations include the company’s joist and deck fabrication operations.

Steel Dynamics, Inc.

CONSOLIDATED BALANCE SHEETS

(in thousands)