The high speed steels listed under the letter symbol "M" generally are considered to have molybdenum as the principle alloying element with equal or slightly greater amounts of tungsten. Its high molybdenium content significantly increases the products' hardness. While our M -2 tool steel product is extremely hard it also resists softening. Cutting edges made with our M -2 product will remain sharp even at elevated temperatures. If your application requires high speed cutting operations, M -2 is an ideal choice.