||TLS 4140 and 4142HT are versatile, alloy steels which are used in variety of tooling and other industrial applications. TLS 4140 is the classic AISI 4140 alloy steel which is sold in the annealed condition at a hardness less than or equal to 217 HBW. TLS 4142HT is a similar steel which is sold prehardened to 28 to 32 HRC (269 to 302 HBW). Pieces of TLS 4142HT which are greater than about 3 inches (76.2mm) in thickness typically exhibit a lower hardness in the central region of the cross section. 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.
Information Provided by Timken Latrobe Steel.Timken sold Latrobe in December 2006. They are now Latrobe Specialty Steels Co.