Exhibit 99.1

Steel Dynamics Reports Significantly Stronger First Quarter 2011 Results

FORT WAYNE, INDIANA, April 18, 2011— Steel Dynamics, Inc. (NASDAQ-GS: STLD) today announced first quarter net income of $106 million, or $0.46 per diluted share on net sales of $2.0 billion. Comparatively, first quarter 2010 net income was $65 million, or $0.29 per diluted share on net sales of $1.6 billion and fourth quarter 2010 net income was $8 million, or $0.04 per diluted share.

First quarter 2011 steel shipments were 1.5 million tons, 4 percent higher than the first quarter of 2010 and 10 percent higher than the fourth quarter of 2010.  The average external steel selling price for the first quarter increased $154 per ton to $890 from the first quarter 2010 average of $736, and increased $137 per ton from the fourth quarter 2010 average of $753.  The first quarter’s average ferrous scrap cost per ton charged increased $86 compared to the first quarter 2010 and $60 in comparison to the fourth quarter 2010 average.

OmniSource ferrous shipments in the first quarter were 1.5 million gross tons, 24 percent higher than the first quarter of 2010 and 23 percent higher than the fourth quarter of 2010.  OmniSource provided 54 percent of the ferrous scrap purchased by SDI’s steel mills during the first quarter.  First quarter non-ferrous shipments were 287 million pounds, 20 percent higher than the first quarter of 2010 and 25 percent higher than the fourth quarter of 2010.

“Our first quarter earnings were significantly higher than our fourth quarter results based on both volumes and margins at our steel and metals recycling operations,” said Keith Busse, Chairman and CEO. “Our steel operations achieved operating income of $196 million, or $138 per ton shipped, a 114 percent increase in operating income over fourth quarter results.  These results were led by our sheet steel and SBQ bar operations. In addition, OmniSource recorded operating income of $49 million, one of our strongest quarters since the economic collapse in the fall of 2008.  The higher steel industry utilization rate continues to strengthen demand for recycled ferrous materials.

“Our Engineered Bar Products and Flat Roll divisions continue to operate at essentially full capacity.  Engineered Bar has maintained its extended order backlog for special-bar-quality steel as demand remains strong.  We are currently planning a 10-day outage at Engineered Bar in April for scheduled maintenance; however, we do not believe this will meaningfully impact second quarter shipments.  Sheet steel demand also continues to be strong as we enter the second quarter.

“Unfortunately, the sustained weakness in the non-residential construction market remains a challenge for our structural and fabrication operations.  Our commitment to rail as a complement to our structural operations remains strong, as first quarter rail shipments were 31,000 tons, our highest quarterly volume so far.  We are encouraged by our progress entering this market, and plan to increase our participation throughout 2011,” Busse said.

The company’s Mesabi Nugget start-up facility in Minnesota resumed operations in January after taking an outage for equipment modifications.  Since the restart, Mesabi has achieved higher facility utilization and improved production volumes.  Nugget shipments increased to 36,000 metric tons in the first quarter from 18,000 metric tons in the fourth quarter of 2010.  Since the beginning of April, the plant has been operating at a monthly rate of 20,000 metric tons.  Mesabi Nugget start-up losses negatively impacted the company’s pre-tax first quarter earnings by $11 million, or approximately $.03 per diluted share, after-tax.

“We are pleased with the continued production improvements at Mesabi.  With the additional supply of liquid pig iron from Iron Dynamics to our flat roll mill, we have nearly achieved our goal of self-sufficiency of iron for our steel operations,” said Busse.

“Looking ahead for 2011, our view remains optimistic. We are seeing the continuation of improvements in the U.S. economy and still anticipate increased steel consumption throughout the year as sectors, such as automotive, transportation, energy, industrial, agricultural, and construction equipment, maintain momentum.  We also expect the second quarter to be solid and will provide quantitative guidance in June,” Busse concluded.

First Quarter 2011 Operating Segment Information

The following highlights first quarter 2011 results for each of SDI’s three primary operating segments. References to segment operating income and operating income per ton in the following paragraphs exclude profit-sharing costs and amortization related to intangible assets.

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, rail, and specialty shapes. Steel operations represented 59 percent of the company’s first quarter 2011 external net sales and 60 percent of the fourth quarter 2010 external net sales.

First quarter 2011 net sales for steel operations were $1.3 billion on shipments of 1.5 million tons, compared to net sales of $1.0 billion on shipments of 1.4 million tons during the same period in 2010 and $979 million in net sales on shipments of 1.3 million tons in the fourth quarter of 2010 (including intra-segment and intra-company sales). The average external steel selling price for the first quarter increased $137 per ton to $890 from the fourth quarter 2010 average of $753. The first quarter’s average ferrous scrap cost per ton charged was $60 higher than the fourth quarter of 2010. First quarter operating income for the steel segment was $196 million, or $138 per ton shipped, compared to $138 million, or $99 per ton, in the first quarter of 2010, and $91 million, or $70 per ton, in the fourth quarter of 2010.

Metals Recycling and Ferrous Resources.  This segment principally includes the company’s metals recycling operations (OmniSource Corporation), liquid pig iron manufacturing facility (Iron Dynamics), and iron nugget manufacturing start-up facility (Mesabi Nugget, which is 81 percent company owned).  First quarter net sales and operating income for the segment were $1.1 billion and $47 million, respectively, as compared to $756 million and $32 million during the first quarter of 2010 and $770 million and a loss of $4 million during the fourth quarter of 2010 (including intra-company sales). The segment represented 37 percent of the company’s first quarter 2011 external net sales and 35 percent of the fourth quarter 2010 external net sales.

OmniSource first quarter 2011 ferrous shipments were 1.5 million gross tons and non-ferrous shipments were 287 million pounds, compared to shipments of 1.2 million gross tons and non-ferrous shipments of 238 million pounds for the first quarter of 2010 and shipments of 1.2 million gross tons and non-ferrous shipments of 230 million pounds for the fourth quarter of 2010.  Forty-four percent and 42 percent of OmniSource’s ferrous scrap shipments were to SDI’s steel mills during the first quarter of 2011 and fourth quarter of 2010, respectively.  During the first quarter, OmniSource supplied 670,000 gross tons of ferrous scrap to SDI’s steel operations, or approximately 54 percent of the tonnage of ferrous scrap purchased by the mills.  Operating income for OmniSource was $49 million during the first quarter of 2011 as compared to $43 million during the first quarter of 2010 and $9 million during the fourth quarter of 2010.

Steel Fabrication Operations.  Steel fabrication operations includes New Millennium Building Systems, which fabricates steel joists, trusses, and decking used in the construction of non-residential buildings. Fabrication operations represented 3 percent of the company’s first quarter 2011 external net sales and 4 percent of fourth quarter 2010 external net sales.

First quarter 2011 net sales for fabrication operations were $53 million on shipments of 44,000 tons, compared to $24 million on shipments of 26,000 tons during the same period in 2010 and $57 million on shipments of 50,000 tons during the fourth quarter of 2010 (including intra-company sales and shipments). First quarter operating losses for the fabrication segment were $3 million, as compared to $7

million in the first quarter of 2010 and $13 million in the fourth quarter of 2010 (which included a non-cash impairment charge of $13 million).

Forward-Looking Statements

This press release contains some predictive statements about future events, including statements related to conditions in the steel and scrap metal markets, Steel Dynamics’ revenues, costs, future earnings, and the operation of new or existing facilities or technologies. 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. Such predictive statements are not guarantees of future performance, and actual results could differ materially from our current expectations.

Factors that could cause such predictive statements to turn out other than as anticipated or predicted include, among others: the effects of a prolonged or deepening recession on industrial demand; conditions in such steel consuming sectors as the automotive, consumer appliance or construction industries; the impact of domestic or foreign import price competition; difficulties in integrating or in realizing anticipated values from acquired businesses; risks and uncertainties involving new products or new technologies; changes in the availability or cost of steel scrap or scrap substitute materials; increases in energy costs; occurrence of unanticipated equipment failures and plant outages; labor unrest; and the effect of the elements on production or consumption.

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, available publicly on the SEC Web site, www.sec.gov, and on the Steel Dynamics Web site, www.steeldynamics.com.

Forward-looking or predictive statements we make are based upon information and assumptions concerning our businesses and the environments in which they operate, which we consider reasonable as of the date on which these statements are made. Due to the foregoing risks and uncertainties however, as well as matters beyond our control which can affect forward-looking statements, we caution you that these statements speak only as of the date hereof.

Conference Call and Webcast

On Tuesday, April 19, 2011, at 10:00 a.m. Eastern time, Steel Dynamics will host a conference call in which management will discuss first quarter results. You are invited to listen to the live audio broadcast of the conference call over the Internet, accessible from the Steel Dynamics Web site:

www.steeldynamics.com

Dial-in information is available on our Web site. An audio replay of the Webcast and a downloadable podcast will be available from the SDI Web site. No telephone replay will be available.

Contact:  Fred Warner, Investor Relations Manager, (260) 969-3564 or fax (260) 969-3590

f.warner@steeldynamics.com

Steel Dynamics, Inc.

CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED)

(in thousands, except per share data)

(Note 1)     Excludes the impact of the 5.125% convertible senior notes from net income (numerator) and share equivalents outstanding (denominator) for the three months ended December 31, 2010, as the impact to diluted earnings per share is anti-dilutive.

Steel Dynamics, Inc.

UNAUDITED SUPPLEMENTAL OPERATING INFORMATION

(dollars in thousands)

Steel Dynamics, Inc.

CONSOLIDATED BALANCE SHEETS

(in thousands)

Steel Dynamics, Inc.

CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED)

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