HIGH SPEED steels have been named to show their ability to resist softening at elevated temperatures therefore maintaining a sharp cutting edge when cuts are heavy and speeds are high. They are the most highly alloyed of all of the tool steel types. They normally contain comparatively large amounts of tungsten or molybdenum, chromium, Cobalt and vanadium, along with carbon.

Two groups are available: Molybdenum Types and Tungsten Types

THE MOLYBDENUM high speed tool steels contain 3.50 to 9.50% molybdenum. They characteristically contain 4.00% tungsten, and 1.00 to 5.00% vanadium. Carbon is fairly high—0.80 to 1.50%. Applications cover a wide range of cutting tools. Examples include these: twist drills, reamers, milling cutters, lathe and planer tools, cutoff knives, and insert cutter blades.

THE TUNGSTEN high speed tool steels have 12.00 to 20.00% tungsten. They also have substantial amounts of chromium and vanadium, and some have considerable amounts of cobalt. Carbon is high—0.70 to 1.50%, depending on the grade. Tooling uses include bits, drills, reamers, taps, broaches, milling cutters, hobs, punches, and dies.

Characterised by the following properties, among other things:

• Very good wear resistance
• High pressure resistance
• Great toughness