US Steel: A Closer Look at Its Four Main Segments United States Steel Corporation, one of the world's largest steel producers, has four primary business segments: North American Flat-Rolled (Flat-Rolled), Mini Mill, U.S. Steel Europe (USSE), and Tubular Products (Tubular). The Flat-Rolled segment is the company's largest division and offers a range of products such as slabs, strip mill plates, sheets, tin mill products, iron ore, and coke. It serves a variety of markets, including transportation, construction, appliances, and electrical. Meanwhile, the Mini Mill segment provides hot-rolled, cold-rolled, and coated sheets, as well as electrical products to customers in different industries such as automotive, construction, and transportation. USSE, the third-largest segment, supplies slabs, strip mill plates, sheets, tin mill products, and spiral welded pipes to clients in the construction, container, and petrochemical markets, among others. Lastly, the Tubular division produces seamless and electric resistance welded steel casing, tubing, line pipe, and mechanical tubing products primarily for the oil, gas, and petrochemical markets. All in all, the company has a diverse portfolio of products and services that cater to different industrial sectors. US Steel, founded in 1901, is headquartered in Pittsburgh, Pennsylvania, and also has a real estate business.