CARPENTER SEVEN STAR is a molybdenum-type high-speed steel containing tungsten. It bears some similarity to AISI Type M1; however, its increased carbon and vanadium percentages (over M1) provide improved cutting efficiency without materially lowering its toughness. Seven Star is an ESR (Electro Slag Remelted) high-speed steel. Its many uses include blanking dies, drills, lathe tools, punches and shearing blades. 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-348. Producer or source: Carpenter.