UNS No. H40320 is a molybdenum (0.20-0.30%) alloy steel that combines moderate hardness and strength with good toughness in the quenched-and-tempered condition. It is relatively free from temper embrittlement when tempered in the susceptible range of approximately 850-1100 F. The automotive industry is one of its main users. 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-354. Producer or source: Alloy steel mills and foundries.