Nucor

Nucor continues to electrify the steel industry with a simple concept: The minimill is mighty. At its various minimills, Nucor produces about 15 million tons of steel annually, including hot- and cold-rolled steel, steel joists, and metal buildings. North America's largest recycler of scrap metal, Nucor produces steel by melting scrap in electric arc furnaces. Most of its products are sold to steel service centers, manufacturers, and fabricators. Subsidiaries such as Vulcraft -- one of the US's largest producers of steel joists, girders, and decking -- use the balance of the steel. The company has grown mainly through acquisition since 2006, including spending $1 billion to buy The David J. Joseph Company.