SAE 8637 is a triple-alloy steel. It can be hardened by quenching in oil or water; however, care must be exercised to prevent cracking in water hardening, especially if the work piece has sharp corners or drastic dimensional changes. This steel has moderate hardenability with relatively high strength and toughness. It is used in the quenching-and-tempered condition for a wide variety of components, parts and tools. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: SA-418. Producer or source: Alloy steel mills and foundries.