Precision Ground Flat Stock
A-2 (AIRTRUE)
Air Hardening Tool Steel
Precision Marshall’s AIRTRUE is an air hardening tool steel which provides a good combination of wear
resistance, toughness, ease of heat treatment and minimum distortion. Special melting and refining practices
are utilized to produce a uniform product with high cleanliness and minimum segregation. The material is
tested to rigorous tool steel standards to ensure uniformity of structure and freedom from defects. Meets ASTM
A-681.
Attributes
EDM
Electro-discharge machining is used in the production of various tooling. This process produces recast, rehardened and retempered layers on the EDM surface. It is recommended that AIRTRUE be stress relieved at 50°F below the final tool tempering temperature, after the EDM process, to temper the rehardened layer produced by EDM.Condition
AIRTRUE A-2 is provided completely decarb free and stress relieved.Chemistry
| ELEMENT | RANGE |
|---|---|
| Carbon | 1.00 |
| Manganese | .60 |
| Phosphorus | .03 max |
| Sulfur | .03 max |
| Chromium | 5.00 |
| Molybdenum | 1.10 |
| Silicon | .30 |
| Vanadium | .35 |
Additional Information
Applications
AIRTRUE is suitable for use in cold work tooling applications requiring a combination of wear resistance and toughness such as thread roll dies, punches, blanking dies, shears and forming dies. The grade is also used for plastic molds requiring high wear resistance.Heat Treating
AIRTRUE is subject to decarburization during heat treatment, so a protective atmosphere furnace or vacuum furnace should be used. After preheating to 1500°F for one half to one hour, heat to 1750/1800°F and soak one half hour when material is up to temperature. Air cool to hand warm (approximately 150°F) and temper immediately.Tempering
Double temper one hour per inch of section thickness to desired harness, two hours minimum per temper.
Representative hardness levels after tempering are tabulated below.
Air cooled from 1750°F • Tempered 4 hours (Section Size — 4” x 4”)
| TEMPERING TEMPERATURE (°F) | ROCKWELL HARDNESS (RC) |
|---|---|
| 400 | 60/62 |
| 500 | 59/61 |
| 600 | 58/60 |
| 700 | 57/59 |
| 800 | 56/58 |
| 900 | 56/58 |
| 1000 | 54/56 |
| 1100 | 47/50 |
