Tool Steel A2

Grade Summary: A2 is a 1% carbon, 5% chrome, air-hardening tool steel. A2 is known as a versatile, general purpose grade and has better resistance to abrasion and wear than the “S” series shock resisting tool steels and more toughness and impact strength than the “D” series wear steels. It is used for a wide range of tooling applications ranging from general purpose punches and dies to components for plastic injection molding. When properly annealed, A2 has a machinability rating of 60 as compared with a 1% Carbon Steel rated at 100. When air quenched from the proper hardening temperature, this grade can be expected to expand approximately .001 in. per in. Note: Distortion (bending, bowing and twisting) as well as part geometry can add to the variations in movement of a part being hardened.

Thermal Cycling: To avoid decarburization, this grade should be annealed and/or hardened in a controlled neutral atmosphere, vacuum or neutral salt furnace environment.

1.  Anneal: Heat to 1650° F. Soak two hours per inch of thickness. Cool 40° F per hour to 900° F. Air cool to room temperature.

2.  Stress Relief of Unhardened Material: Heat slowly to 1200° to 1250° F. Soak for two hours per inch of thickness at heat. Slow cool (furnace cool if possible) to room temperature.

3.  Hardening:

  • Preheat: Heat to 1200° F. Hold at this temperature until thoroughly soaked.
  • Harden: Heat to 1750° to 1800° F. Soak at heat for 45 to 60 minutes per inch of greatest thickness.
  • Quench: Air quench to 150° F. Temper immediately.
  • Temper: Double temper is mandatory. Soak for two hours per inch of thickness at heat. Slow cool to room temperature between tempers.

Specimens 1” diameter were quenched from 1775° F.

4. Stress Relief Temper: A stress relief temper for hardened material is strongly recommended after significant grinding, or welding, or EDM. Select a temperature that is 25°or 50° F lower than the last tempering temperature used.

Available products: Round Bar, Drill Rod, Rectangular Bar, Ground Flat Bar, Square Bar and Plate

Typical Chemical Analysis: * C – 1.00 *Mo – 1.00 *Cr – 5.0 *V – .20

* Chemical Analysis will vary.

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