FAGERSTA WKE-4 is a tungsten-molybdenum high-speed steel containing 9% cobalt. It is harder than most high-speed steels and, in addition, has good toughness. It is used mainly for tools requiring maximum abrasion resistance and toughness, such as milling cutters, twist drills and reamers. This datasheet provides information on composition and hardness. It also includes information on forming, heat treating, and machining. Filing Code: TS-311. Producer or source: Fagersta Steels Inc..