Hot rolled steel is divided into structural steel, mild steel and welded bottle steel. Then, according to various steels, find the steel you need, and check the density and composition of the specific steel. Hot rolled steel plate has low hardness, easy processing and good ductility. Cold rolled plate hardness is high, processing is relatively difficult, but not easy to deformation, high strength. Hot rolled steel plates have relatively low strength and poor surface quality (low oxidation finish), but good plasticity. Generally for medium thick plate, cold rolled plate, high strength, high hardness, high surface finish, generally for thin plate, can be used as punching plate. The production process of hot-rolled steel plate is different from that of cold-rolled steel plate. Hot rolled steel plate is high temperature rolling, cold rolled steel plate is room temperature frying