AISI 4028 is a molybdenum (0.20-0.30%) alloy steel containing 0.035-0.050% sulfur to provide improved and less variable machinability over a similar steel specified at 0.040% sulfur max. It combines moderate strength with good toughness in the quenched-and-tempered condition because it is relatively free from temper embrittlement when tempered in the range 850-1100 F. The automotive industry is one of its applications. 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-333. Producer or source: Alloy steel mills and foundries.