U. S. S. SUPERKORE comprises a series of six low alloy, deep hardening carburizing steels that have shown hardenability equal to or slightly greater than the conventional alloy steels which they are designed to replace, as shown under General Characteristics. This datasheet provides information on composition, hardness, and tensile properties as well as fracture toughness. It also includes information on heat treating, machining, and joining. Filing Code: SA-10. Producer or source: United States Steel Corporation.