SAE 4135 is a medium-carbon chromium-molybdenum alloy steel for heavy-duty service. Although nominally an oil-hardening grade, it may be water hardened if proper precautions are exercised. It is used for a wide variety of engineering applications. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: SA-316. Producer or source: Alloy steel mills and foundries.