Exhibit 99.1

Steel Dynamics Reports Record Second Quarter 2018 Financial Results

FORT WAYNE, INDIANA, July 23, 2018 / PRNewswire / Steel Dynamics, Inc. (NASDAQ/GS: STLD) today announced second quarter 2018 financial results.  The company reported second quarter 2018 net sales of $3.1 billion and net income of $362 million, or $1.53 per diluted share.  Comparatively, prior year second quarter net income was $154 million, or $0.63 per diluted share, with net sales of $2.4 billion.  Sequential first quarter 2018 net income was $228 million, or $0.96 per diluted share, with net sales of $2.6 billion.

“The team performed exceptionally well during the quarter,” said Mark D. Millett, President and Chief Executive Officer.  “Our second quarter 2018 income from operations increased 55 percent sequentially to a record $502 million, and adjusted EBITDA increased to a record $590 million.  During the second quarter, we saw improved demand and product pricing across the entire steel platform, resulting in record quarterly steel shipments and significant margin expansion. While we saw improvement from each of our steel divisions, the increase in earnings was principally driven by our flat roll operations, as continued strong demand supported meaningful volume and margin expansion.  Domestic steel demand remained strong from the automotive, construction, and energy sectors, while general industrial demand continued to grow.

“The metals recycling platform also performed well, with strong shipments and continued steady operating costs; although, higher unprocessed scrap procurement costs offset some of these benefits,” continued Millett.  “As we suggested on the first quarter earnings call, our fabrication platform earnings were negatively impacted in the second quarter, as a result of higher average steel input costs, as steel prices continued to increase throughout the quarter.  However, fabrication demand is strong, and our customer base continues to be optimistic concerning project development throughout the second half of the year.

“I also want to again welcome the Heartland team and customers into our SDI family,” said Millett. “We successfully completed the acquisition of the Heartland steel finishing assets located in Terre Haute, Indiana on June 29, 2018.  We are excited about the opportunities that Heartland, together with our Midwest flat roll operations, provides us. The acquisition levers our core strengths and further increases our value-added product and market diversification.”

Second Quarter 2018 Comments

Second quarter 2018 operating income for the company’s steel operations increased 59 percent sequentially to a record $537 million, based on an eight percent increase in shipments and metal spread expansion, as average steel product pricing increased more than consumed raw material scrap costs.  The second quarter 2018 average product selling price for the company’s steel operations increased $110 to $932 per ton.  The average ferrous scrap cost per ton melted increased $27 to $348 per ton.

Second quarter 2018 operating income attributable to the company’s flat roll steel operations increased 67 percent sequentially, driven by metal spread expansion related to continued strong underlying demand, higher selling values and a five percent increase in shipments. Operating income from the company’s long product steel operations increased 36 percent, as a result of improved shipments and metal spread expansion, primarily from the company’s Structural and Rail Division.  The company’s steel production utilization rate was 99 percent in the second quarter 2018, compared to 94 percent in the sequential first quarter and 91 percent in the second quarter of 2017.

Second quarter 2018 operating income from the company’s metals recycling operations was $26 million, compared to $28 million in the sequential first quarter.  Higher procurement costs offset a seven percent increase in recycled ferrous shipments, resulting from strong domestic steel mill demand.

The company’s fabrication operations recorded second quarter 2018 operating income of $14 million, compared to sequential first quarter results of $20 million, as improved average selling values and higher shipments were more than offset by higher steel input costs.

Year-to-Date June 30, 2018 Comparison

For the six months ended June 30, 2018, net income was $590 million, or $2.49 per diluted share, on net sales of $5.7 billion, as compared to net income of $355 million, or $1.46 per diluted share, on net sales of $4.8 billion for the same period in 2017.  First half 2018 net sales increased across all operating platforms, with the 20 percent improvement driven by higher average steel product pricing and record steel shipments.  First half 2018 operating income increased 38 percent to $825 million, based on improved earnings from the company’s steel operations. The average year-to-date selling price for the company’s steel operations increased $118 to $879 per ton.  The average year-to-date ferrous scrap cost per ton melted increased $51 to $334 per ton.

During the first half of 2018, the company generated strong cash flow from operations of $504 million and maintained liquidity of $2.0 billion at June 30, 2018.  On June 29, 2018, the company used available cash of $396 million to fund the acquisition of Heartland.  The company also repurchased $118 million of its common stock during the first half of 2018.

Outlook

“We remain confident that macroeconomic and market conditions are in place to benefit domestic steel consumption,” said Millett.  “Based on strong domestic steel demand fundamentals and customer optimism, we believe steel consumption will continue to be strong for the remainder of the year.  Domestic steel inventory levels also remain reasonably balanced.  In combination with our expansion initiatives, we believe there are firm drivers for our continued growth.  We are excited about Heartland and our recently announced expansion plans at the Columbus Flat Roll Division.  These actions represent a few steps in the continuation of our growth initiatives, to further increase value-added products and market diversification.

“As it relates to Heartland, we believe this acquisition will result in numerous future earnings benefits both to Heartland’s current operations and to our broader Midwest flat roll operations.  In combination, Heartland brings a tremendous amount of operating flexibility and optionality ultimately providing recurring synergies.  We are integrating Heartland into our Midwest flat roll operations, and plan to focus our value-added, lighter gauge flat roll production at Heartland, which while increasing profitability will likely result in less than nameplate cold mill volume at Heartland.  We currently plan to increase production during the second half of 2018 to approximately 40,000 tons per month, with the expectation to reach an annual run-rate of between 800,000 tons and 900,000 tons of cold roll, pickled and oiled, and galvanized flat roll steel by mid-year 2019.  Based on our current purchase price allocation estimates, we currently expect third quarter 2018 earnings contribution from Heartland to be reduced by approximately $12 million to $15 million (pre-tax), due to fair value accounting adjustments.  On a through-cycle basis, we believe the increased benefit of the Heartland acquisition will ultimately improve our through-cycle EBITDA between $50 million and $60 million per year.

“We continue to strengthen our financial position through strong cash flow generation and the execution of our long-term strategy. We are well-positioned for growth, and remain focused on delivering shareholder value through organic and transactional growth opportunities,” concluded Millett.

Conference Call and Webcast

Steel Dynamics, Inc. will hold a conference call to discuss second quarter 2018 operating and financial results on Tuesday, July 24, 2018, at 10:00 a.m. Eastern Time.  You may access the call and find dial-in information on the Investors section of the company’s website at www.steeldynamics.com.  A replay of the call will be available on our website until 11:59 p.m. Eastern Time on July 29, 2018.

About Steel Dynamics, Inc.

Steel Dynamics 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 facilities located throughout the United States, and in Mexico.  Steel Dynamics produces steel products, including hot roll, cold roll, and coated sheet steel, structural steel beams and shapes, rail, engineered special-bar-quality steel, cold finished steel, merchant bar products, specialty steel sections and steel joists and deck.  In addition, the company produces liquid pig iron and processes and sells ferrous and nonferrous scrap.

Note Regarding Non-GAAP Financial Measures

The company reports its financial results in accordance with U.S. generally accepted accounting principles (GAAP). Management believes that Adjusted Net Income, Adjusted Diluted Earnings Per Share, EBITDA and Adjusted EBITDA, non-GAAP financial measures, provide additional meaningful information regarding the company’s performance and financial strength. Non-GAAP financial measures should be viewed in addition to, and not as an alternative for, the company’s reported results prepared in accordance with GAAP.  In addition, because not all companies use identical calculations, EBITDA and Adjusted EBITDA included in this release may not be comparable to similarly titled measures of other companies.

Forward-Looking Statements

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, which we generally precede or accompany by such typical conditional words as “anticipate,” “intend,” “believe,” “estimate,” “plan,” “seek,” “project” or “expect,” or by the words “may,” “will,” or “should,” 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: (1) the effects of uncertain economic conditions; (2) cyclical and changing industrial demand; (3) changes in conditions in any of the steel or scrap-consuming sectors of the economy which affect demand for our products, including the strength of the non-residential and residential construction, automotive, manufacturing, appliance, pipe and tube, and other steel-consuming industries; (4) fluctuation in the cost of key raw materials and supplies (including steel scrap, iron units, and energy costs) and our ability to pass on any cost increases; (5) the impact of domestic and foreign import price competition; (6) unanticipated difficulties in integrating or starting up new or acquired businesses; (7) risks and uncertainties involving product and/or technology development; and (8) occurrences of unexpected plant outages or equipment failures.

More specifically, we refer you to Steel Dynamics’ 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 under the headings Special Note Regarding Forward-Looking Statements and Risk Factors, 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 website, www.sec.gov, and on the Steel Dynamics website, www.steeldynamics.com: Investors: SEC Filings.

Contact:  Tricia Meyers, Investor Relations Manager— +1.260.969.3500

Steel Dynamics, Inc.

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