AISI Type M33 is a heavy-duty high-speed steel; it contains 8.00% cobalt to improved red hardness. It is recommended for cutting-tool applications in which wear resistance and high temperature hardness are important characteristics. It should not be used where excessive shock and/or chatter are encountered. AISI Type M33 is well suited to uses such as machining hard and heat-treated materials and machining both ferrous and nonferrous aircraft alloys. This datasheet provides information on composition, physical properties, hardness, and elasticity as well as fracture toughness. It also includes information on forming, heat treating, and machining. Filing Code: TS-402. Producer or source: Tool steel mills.