HY-TEN B Temper No. 3X-40 is a medium-carbon alloy steel having free-cutting characteristics. It is recommended for machine tools, mining and road building equipment, gears, crankshafts, bolts, etc. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on forming, heat treating, machining, and joining. Filing Code: SA-248. Producer or source: Wheelock, Lovejoy & Company Inc..