Superior Aluminum Alloys Recognized by General Motors as a 2012 Supplier of the Year Winner

Steel Dynamics, Inc. (the company) (NASDAQ/GS: STLD) announced today that General Motors recognized one of the company’s subsidiaries, Superior Aluminum Alloys LLC, as one of its best global automotive suppliers on Wednesday, March 13 during its 21(st) annual Supplier of the Year awards ceremony. The event was held at the Charles H. Wright Museum of African American History in Detroit.

“We are honored to have received this award from General Motors, Inc., one of our valued customers, ” said Denny Luma Vice President of OmniSource and President of Superior Aluminum Alloys. “We appreciate being recognized for our quality products. At our Superior facility, we operate the most advanced technology in every one of our processes. More importantly, our employees have an unyielding passion for producing the highest quality products and services for our customers. Their attention to detail shows in everything we do.”

“We are very proud of our employees for achieving the highest recognition from General Motors, Inc. afforded a supplier,” stated Russ Rinn, Executive Vice President of Steel Dynamics and President and COO of OmniSource. “Denny and his team have demonstrated that the combination of our outstanding people, our technology and our quality systems ensure we maintain the highest standards of excellence for our customers.”

Superior Aluminum Alloys was one of only 83 suppliers recognized by GM who have consistently exceeded GM’s expectations by being innovative, delivering quality products and services on time and by creating outstanding value. This is the first time Superior Aluminum Alloys has received the Supplier of the Year award.

“Superior Aluminum Alloys helped play a critical role in GM’s success in 2012 through their dedication and commitment to consistently exceed our expectations by being innovative, delivering high quality products and services on time and by creating outstanding value,” said Grace Lieblein, GM vice president, Global Purchasing and Supply Chain. “We are thrilled to recognize Superior Aluminum Alloys, who we consider to be a world-class supplier.”

The Supplier of the Year award is given to less than 1 percent of GM’s approximately 18,500 suppliers around the world. The winners are recognized for delivering innovative technology, superior quality, timely crisis management and competitive, total-enterprise cost solutions.

Superior Aluminum Alloys is a secondary-aluminum smelting producer, manufacturing approximately 260 million pounds per year of certified aluminum alloys in the form of ingots, sows, deox cones, and molten metal. The unit was formed by OmniSource in 1998 and has rapidly developed an outstanding reputation in the secondary-aluminum industry.

The Supplier of the Year winners are chosen by a global team of GM purchasing, engineering, quality, manufacturing and logistics executives.

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 $7.3 billion in 2012, over 6,600 employees, and manufacturing facilities primarily located throughout the United States (including five steel mills, six steel processing facilities, two iron production facilities, over 70 metals recycling locations and six steel fabrication plants).

About General Motors Co.

General Motors Co. (NYSE: GM, TSX: GMM) and its partners produce vehicles in 30 countries, and the company has leadership positions in the world’s largest and fastest-growing automotive markets. GM’s brands include Chevrolet and Cadillac, as well as Baojun, Buick, GMC, Holden, Isuzu, Jiefang, Opel, Vauxhall and Wuling. More information on the company and its subsidiaries, including OnStar, a global leader in vehicle safety, security and information services, can be found at http://www.gm.com