AISI 4142 is a medium-carbon low-alloy steel recommended for moderately heavy-duty service. It is nominally an oil-hardening grade; however, it may be water hardened if suitable precautions are taken to avoid cracking. It has a relatively low tendency to develop temper embrittlement. It has a variety of applications including bolts, crankshafts, wrenches, clutch parts and shafting. 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, and joining. Filing Code: SA-370. Producer or source: Alloy steel mills and foundries.