|
Technical
Information on A-6 Tool Steel
 | A-6 is an air-hardening die steel with excellent
non-deforming properties. Typical analysis is shown in the chart below: |
| Carbon |
Silicon |
Manganese |
Chromium |
Molybdenum |
| 1% |
0.2% |
0.6% |
5.3% |
1.1% |
| A-6 is used in applications requiring wear resistance
and toughness, and where distortion in heat treatment must be minimized. Typical
applications are:
 | Blanking Dies |
| Thread Roll Dies |
| Coining Dies |
| Drawing Dies |
| Forming Dies |
| Shear Blades |
| Plastic Molds |
| Precision Tools |
| Gauges |
|
| Heat Treatment
| Forging:
 | Heat slowly to 2025º F. |
| Allow steel to heat through before forging. |
| DO NOT hot work A-6 below 1650º F. |
| After forging, allow A-6 to cool slowly in furnace or
buried in ashes, lime, etc. |
| Anneal as soon as possible. |
|
| Annealing:
| Slowly heat A-6 to 1350º - 1400º until piece is
uniformly heated through. |
| Cool slowly in furnace at 20º/hour to 1000ºF, and
then air cool to to room temperature. |
| Annealed hardness ranges between 200 - 230 Brinell. |
|
| Stress Relieving:
| Heat slowly to 1150ºF - 1250ºF, hold at least one
hour per inch of maximum dimension, cool in still air. |
|
| Hardening:
| Surface protection: pack hardening or controlled
atmosphere furnaces. |
| Pre-heat slowly to 1200ºF, then increase heat to
hardening temperature of 1525ºF-1600ºF. |
| Hold steel at hardening temperature for 1 hour, cool in still
air, temper when piece has reached 150ºF. |
| As-hardened hardness should be about 60 - 63 Rockwell
C, depending on piece size. |
|
| Tempering:
| Temper immediately after hardening |
| Best combination of toughness and hardness is achieved
at tempering temperatures between 350ºF - 400ºF, with Rockwell C between 50 - 60. |
| Heat slowly to temperature. |
| Hold tools at temperature for 1 hour per inch of cross
section (minimum 2 hours). |
| Cool slowly to room temperature. |
|
|
| Physical & Mechanical
Properties:
| Density, lb per cu in: .290 |
| Specific gravity 7.85 |
|
| EDM
| EDMing produces a recast (melted and rehardened) layer
on the steel. EDM'd pieces should be retempered at 50ºF under the final tempering
temperature to prevent cracking due to stress caused by the recast layer, and stoned to
remove recast layer. |
|
| Mean Thermal Coefficient of
Expansion
Range |
Coefficient x 10-6 |
ºF |
in./in./ºF |
68 –212 |
6.57 |
68S392 |
6.91 |
68S572 |
7.32 |
68S752 |
7.59 |
68S932 |
7.86 |
68S1112 |
8.01 |
68S1292 |
8.19 |
|
|
