AISI 8642 is a triple-alloy steel that can be hardened by austenitizing and quenching in oil. This steel has moderate hardenability with relatively high strength and toughness, especially in the quenched-and-tempered condition. It is used in a wide range of components, parts and tools; examples are bolts, shafts, gears, wrenches, axles and housings. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on heat treating, machining, joining, and surface treatment. Filing Code: SA-440. Producer or source: Alloy steel mills and foundries.