Exhibit 99.1

Steel Dynamics Reports Second Quarter 2011 Results

FORT WAYNE, INDIANA, July 18, 2011— Steel Dynamics, Inc. (NASDAQ-GS: STLD) today announced second quarter net income of $99 million, or $0.43 per diluted share, on net sales of $2.1 billion. By comparison, second quarter 2010 net income was $49 million, or $0.22 per diluted share, on net sales of $1.6 billion, and first quarter 2011 net income was $106 million, or $0.46 per diluted share, on net sales of $2.0 billion.

On a consecutive quarterly basis, unrealized hedging gains at the company’s metals recycling operations were $9.5 million during the first quarter of 2011, as compared to an unrealized hedging loss of $4.8 million in the second quarter of 2011, resulting in a non-cash fluctuation in the company’s pretax earnings of $14.3 million, an estimated impact of approximately $0.04 per diluted share between quarters. Additionally, the company reduced its deferred income tax provision due to recent changes in Indiana tax law, which increased second quarter earnings approximately $0.01 per diluted share.

Second quarter 2011 steel shipments were 1.5 million tons, 15 percent higher than the second quarter of 2010 and nearly the same as the first quarter of 2011. The average external steel selling price per ton shipped for the second quarter increased $118 per ton to $947 from the second quarter 2010 average sales price of $829, and increased $57 per ton from the first quarter 2011 average sales price of $890.

Based on the tons of scrap melted at the five steel mills, the second quarter’s average ferrous scrap cost per ton charged increased $51 compared to the second quarter 2010, and increased $15 compared to the first quarter of 2011.

OmniSource’s ferrous shipments in the second quarter were 1.6 million gross tons, 15 percent higher than the second quarter of 2010 and 2 percent higher than the first quarter of 2011. OmniSource provided 54 percent of the ferrous scrap purchased by SDI’s steel mills during the second quarter.  Second quarter non-ferrous shipments were 255 million pounds, 8 percent higher than the second quarter of 2010, but 11 percent lower than the first quarter of 2011.

“Quarter over quarter operational earnings were essentially the same, although from different sources,” said Keith Busse, Chairman and CEO. “Operating income from our steel operations increased $21 million but was offset by a decrease in our metals recycling and ferrous resources operations of $36 million.  Operating performance of our steel operations improved in the second quarter, resulting in operating income of $217 million, or $153 per ton shipped, a 62 percent increase versus the same quarter last year and an 11 percent increase compared to the first quarter of 2011.

“We experienced some volatility in order bookings for flat-rolled steel during the second quarter, while bookings for other steel operations remained steady or slightly improved. While structural steel shipments of 179,000 tons were up 11 percent from the first quarter of 2011, demand for structural steel remains weak, causing our Structural and Rail Division to continue to operate well below its capacity. Augmenting the division’s revenues were rail shipments of 35,000 tons, up 14 percent compared to the first quarter of 2011. For the Engineered Bar Products Division, second quarter shipping volume of 144,000 tons was lower than the first quarter’s shipments of 159,000 tons due to a planned 10-day maintenance and equipment upgrade outage.  SBQ demand and the mill’s order backlog remain very strong,” Busse said.

“Operating income for OmniSource was $18 million in the second quarter, a decrease of $7 million in comparison to the second quarter of 2010, and a decrease of $31 million in comparison to the nearly record high achieved in the first quarter of 2011,” said Mark Millett, President and Chief Operating Officer.  “Second quarter non-ferrous stainless margins and shipping volumes decreased as a result of weaker demand from stainless mills, which were carrying higher than normal inventory levels.  As destocking occurs, we anticipate renewed ordering activity during the third quarter.  Additionally, while ferrous

shipping volumes increased slightly, margins compressed in comparison to those achieved in the first quarter of this year, which benefited from the sale of lower priced inventory into the strong January market.

“In our raw materials platform, Iron Dynamics continues to provide a consistent supply of liquid pig iron to the Flat Roll Division. We are also seeing progress made at the Mesabi Nugget operation. Second quarter production of iron nuggets increased to 38,000 metric tons, most of which shipped in April and June, as the planned May furnace reline outage lasted about three weeks. Start-up losses incurred by Mesabi Nugget in the second quarter negatively impacted consolidated earnings by $13 million, or approximately $0.03 per diluted share, after-tax. We expect nugget production volume to continue to improve in the second half of the year, and have an additional outage planned for September to install equipment that should further improve plant utilization,” Millett said.

“Looking ahead to the second half of 2011,” Busse said, “we believe continued slow improvement in the U.S. economy is possible and anticipate continued, yet uneven, buying activity as service center inventory levels remain relatively low, and consumption by such sectors as automotive, transportation, energy, industrial, agricultural, and construction equipment remains steady to growing slightly.  We will provide quantitative guidance regarding the third quarter in September, but barring any unforeseen changes in the economic climate, the third quarter should be fairly solid,” Busse concluded.

Second Quarter 2011 Reporting Segment Information

The following highlights second quarter 2011 results for each of SDI’s three primary reporting 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 61 percent of the company’s second quarter 2011 external net sales and 59 percent of external net sales in the first quarter 2011.

Second quarter 2011 net sales for steel operations were $1.4 billion on shipments of 1.5 million tons, compared to net sales of $1.0 billion on shipments of 1.3 million tons during the same period in 2010, and $1.3 billion in net sales on shipments of 1.5 million tons in the first quarter of 2011 (including intra-segment and intra-company sales). The average external steel selling price for the second quarter increased $57 per ton to $947 from the first quarter 2011 average of $890. The second quarter’s average ferrous scrap cost per ton charged was $15 higher than the first quarter of 2011. Second quarter operating income for the steel segment was $217 million, or $153 per ton shipped, compared to $134 million, or $108 per ton, in the second quarter of 2010, and $196 million, or $138 per ton, in the first quarter of 2011.

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).  Second quarter net sales and operating income for the segment were $1.1 billion and $11 million, respectively, as compared to $848 million and $15 million during the second quarter of 2010, and $1.1 billion and operating income of $47 million during the first quarter of 2011 (including intra-segment and intra-company sales). The segment represented 35 percent of the company’s second quarter 2011 external net sales versus 37 percent of the first quarter 2011 external net sales.

OmniSource’s second quarter 2011 ferrous shipments were 1.6 million gross tons and non-ferrous shipments were 255 million pounds, compared to ferrous shipments of 1.4 million gross tons and non-ferrous shipments of 237 million pounds for the second quarter of 2010, and ferrous shipments of 1.5 million gross tons and non-ferrous shipments of 287 million pounds for the first quarter of 2011. OmniSource’s ferrous scrap shipments to SDI’s steel mills were 42 percent of its ferrous scrap shipments during the second quarter versus 44 percent in the first quarter of 2011. During the second quarter, OmniSource supplied 655,000 gross tons of ferrous scrap to SDI’s steel operations, or approximately 54

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percent of the tonnage of ferrous scrap purchased by the mills. Operating income for OmniSource for the second quarter of 2011 was $18 million as compared to $25 million during the second quarter of 2010 and $49 million in the first quarter of 2011.

Steel Fabrication Operations.  The New Millennium Building Systems steel fabrication operations fabricate steel joists, trusses, and decking used in the construction of non-residential buildings. Fabrication operations represented 3 percent of the company’s external net sales for both the first and second quarters of 2011.

Second quarter 2011 net sales for fabrication operations were $62 million on shipments of 48,000 tons, compared to $42 million on shipments of 42,000 tons during the same period in 2010, and $53 million on shipments of 44,000 tons during the first quarter of 2011 (including intra-company sales and shipments). Second quarter operating losses for the fabrication segment were $2 million, as compared to $5 million in the second quarter of 2010, and $3 million in the first quarter of 2011.

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, July 19, 2011, at 10:00 a.m. Eastern time, Steel Dynamics will host a conference call in which management will discuss second 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

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CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED)

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UNAUDITED SUPPLEMENTAL OPERATING INFORMATION

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CONSOLIDATED BALANCE SHEETS

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CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED)

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