LSS™ 4140 and 4142HT Alloy Steels

LSS 4140 and 4142HT are versatile, alloy steels that are used in a variety of tooling and other industrial applications. LSS 4140 is the classic AISI 4140 alloy steel that is sold in the annealed condition at a hardness less than or equal to 217 HBW. LSS 4142HT is a similar steel which is sold prehardened to 28 to 32 HRC (269 to 302 HBW). Pieces of LSS 4142HT that are greater than about 3 inches (76.2mm) in thickness typically exhibit a lower hardness in the central region of the cross section.

Applications: Typical applications for these steels include break dies, bending dies, support tooling, die holders, gears, flanges, collets, arbors, spindles, axles, clutch parts, forming rolls, wrenches and other hand tools, and various machine tool components.

Composition

Physical Properties

• Density: 0.283 lb/in³ (7833 kg/m³)
• Specific Gravity: 7.83
• Modulus of Elasticity: 29 x 10⁶ psi (200 GPa)

Machinability: 60 - 65% of a 1% carbon steel