According to the shape of the steel bar can be divided into channel steel, I-steel, rebar, round steel, wire, square steel, Angle steel and other different types. Among them, channel steel is famous for its cross section like groove, which has good mechanical properties and welding properties, etc., and is widely used in building structures and mechanical equipment. Rebar surface is crescent, spiral shape, etc., with high strength, good toughness and other advantages, is widely used in housing, Bridges, roads and other civil engineering.