Steel Dynamics, Inc. (SDI) is an American steel producer based in Fort Wayne, Indiana. With a production capacity of 13 million tons of steel, the company is the third largest producer of carbon steel products in the United States. It is among the most profitable American steel companies in terms of profit margins and operating margin per ton. Based on its 2021 revenue, the company ranked 196th on the 2022 edition of the Fortune 500.
Description from Wikipedia