O-1 Tool Steel
Chemical Composition
Carbon (C)            .85/1.00
Manganese (Mn)  1.00/1.40
Silicon (Si)              .50 max
Tungsten (W)         .40/.60
Molybdenum (Mo)
Chromium (Cr)       .40/.60
Vanadium (V)         .30 max
Cobalt (Co)
*Nickel (Ni)            .30 max
*Unless otherwise specified, nickel plus copper equal 0.75% max. for all tool steel types
O-1 is typically bought to meet chemistry requirements rather than physical requirements. For that reason, physical properties are generally not provided unless requested prior to production. Any material can be sent to a third party after production to be tested for physical properties.
Typical Uses
Typical Applications for O-1 Tool Steel include:
  • Blanking Dies
  • Bushings
  • Forming Dies
  • Master Tools
  • Forming Rolls
  • Gauges
  • Trim Dies

Oil-Hardening Tool Steel

O1 grade steel is an oil-hardening, non-deforming tool steel. It is considered to be a "non-shrinking" steel and it can be hardened to a Rockwell Range of C 65 through use of relatively low temperatures. Tools and dies made from O1 will have good wearing qualities since the tungsten and higher chromium content gives improved wear resistance over the straight manganese grades. O1 is typically selected for its good combination of strength, hardness and wear resistance. O-1 is available in a standard finish as well as a flat ground stock and drill rod. These are precision ground to a fine surface.