Typical Analysis: C 1.00, Mn .70, Cr 5.00, Mo 1.10, V .25. A-2 Tool Steel is a general purpose, 5% chrome air hardening tool steel. A-2 is popular because it has better wear resistance compared to S-7, A-6 and A-8 Tool Steel. A-2 is tougher and more ductile that D-2 Tool Steel. A-2 is also a very safe grade of tool steel to harden, and can be heat treated in most tool room furnaces without problem. When compared to a 1% carbon steel, A-2 has a machinability rating of 65. Preheat: 1200°F until thoroughly soaked. Harden at 1775°F. Hold 20 minutes/inch of greatest cross-section after tool reaches furnace temperature (min. holder time-30 mins). Air quench to 150°F. Temper immediately 2 hrs./inch of greatest cross-section at temps. shown to achieve the desired hardness.
