SAE 4427 is a 0.5% molybdenum steel designed for carburizing applications and it is also useful for general purposes. It is recommended for case-hardened gears, pinions, shafts and similar components. 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-306. Producer or source: Alloy steel mills and foundries.