Steel castings are especially adapted for parts that must withstand wear, shocks or heavy loads.They are stronger than either wrought iron or cast iron or malleable iron and are very tough. High alloy Steel castings can be heat treated to bring about the diffusion of carbon or alloying elements, softening, hardening, stress relieving, toughening, improve machinability, increase wear resistance, and removal of hydrogen entrapped at the surface of the casting.