By far the most important coated product of the steel mill is plate for the manufacture of containers. Other processes of steel fabrication include forging, founding, and drawing the steel through dies. The physical properties of various types of steel and of any given steel alloy at varying temperatures depend primarily on the amount of carbon present and on how it is distributed in the iron. Steels are grouped into five main classifications. More than 90 percent of all steels are carbon steels.
Alloy steels have a specified composition, containing certain percentages of other elements.
They have been specially processed, however, to have much more strength than carbon steels of the same weight. Stainless steels contain chromium, nickel, and other alloying elements that keep them bright and rust resistant. Tool steels are fabricated into many types of tools, or into the cutting and shaping parts of power-driven machinery for manufacturing. They contain alloying elements that give them extra strength, hardness, and resistance to wear. Tempering decreases hardness and strength, but increases ductility and toughness.