CARPENTER STAR-ZENITH is an 18% tungsten-4% chromium-1% vanadium type of high-speed steel that, because of the practice used in its manufacture, has improved toughness to provide it with a stronger, keener cutting edge than is furnished by conventional steel manufacturing practice. For this reason hundreds of users have found it to be an excellent high-speed steel for broaches, form tools, reamers, taps and similar tools. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on forming, heat treating, machining, and surface treatment. Filing Code: TS-382. Producer or source: Carpenter.