Die steel is used to make moulds such as cold stamping die, hot forging die anddie casting die. Die steel can be roughly divided into three types including cold rolled diesteel, hot rolled die steel and plastic mould steel, using for forging, stamping, cutting, diecasting, etc. Due to the different usages and the complicated working conditions of themoulds, the die steel used for moulds should have high hardness, strength, abrasionresistance, enough toughness, high hardenability, high hardening capacity and otherprocess properties.