America's iron and steel industry produces everything from processed iron ore to steel ingots, sheets, rods, bars, and plates in a number of alloy configurations. In this country, steel ranks among the 10 largest industries. There are two major categories of steel producers: --Integrated steel makers that convert iron ore into steel through a lengthy process that employs a blast furnace to produce iron from iron ore and a basic oxygen or open-hearth furnace to transform the iron into steel. -- Non-integrated steel makers that melt steel scrap in an electric arc furnace or produce liquid steel in facilities that sometimes are known as "minimills." Since World War II, the expansion of foreign steel industries created heavy competition for the U.S. industry.