United States Steel Corp operates primarily in the United States but also has steelmaking capacity in Slovakia. The company's operating segments include Flat-Rolled; USSE and Tubular. It generates maximum revenue from the Flat-Rolled segment. The Flat-Rolled segment includes U. S. Steel's integrated steel plants and equity investees in North America involved in the production of slabs, strip mill plates, sheets, and tin mill products, as well as all iron ore and coke production facilities in the United States. It primarily serves North American customers in the service center, conversion, transportation, construction, container, and appliance and electrical markets.