CRUCIBLE CSM®6
(AISI A6)
CSM 6 is an air hardening tool steel offering moderate wear resistance and toughness. It may be hardened from a low hardening temperature for easy heat treatment.
Typical Chemistry
Carbon 0.70%
Manganese 2.00%
Silicon 0.30%
Chromium 1.00%
Molybdenum 1.35%
Typical Applications
Punches Dies
Compression Molds Lens Molds
Injection Molds
Transfer Molds

Hardening

Preheat: 1200/1300F, equalize.

High Heat: 1550/1625F, hold 30/45 at temperature

Quench: Air, positive pressure vacuum. Cool to 150F.

Temper: 300/1000F, hold one hour/inch of thickness (two hours minimum), air cool to room temperature. Two tempers are recommended.
Size Change During Hardening

Hardening
Temp.
Tempering
Temp.
HRC
Longitudinal
Size Change
%
°F
°C
°F
°C

1550
845
300
150
60
+.05
1550
845
500
260
56
+.11
1550
845
700
370
54
+.05

Typical Properties

Tempering
Temp.
Hardness
HRC
Charpy C-notch
Toughness,
ft-lbs
°F
°C

200 102 61
300 150 60 27
400 205 58 44
500 260 56 60
600 315 55 67
700 379 54
800 425 52
900 480 50
1000 540 48

Surface Treatments
Because of the low tempering temperatures normally used, CSM 6 is not normally suitable for nitriding or other similar surface treatments.

Annealing
Heat to 1425F, hold two hours, cool slowly (20F/hour maximum) to 1100F, air cool to room temperature.

Typical annealed hardness: 217/248 BHN.

Stress Relieving
Annealed Material: Heat to 1200/1250F, hold two hours, cool in still air.

Heat Treated Material: Heat 25/50F below tempering temperature, hold two hours, cool in still air.

Welding
For Annealed Material: Preheat 400 to 600F and maintain heat throughout welding process. Use air hardening tool steel filler metal like A8. Re-anneal at 1200F for 6 hours after welding.

For Hardened Material: Care must be taken with dies of complex design. Pre-heat to 400F minimum or 50F below original tempering temperature if higher than 400F. Use small diameter weld rod and after welding let cool to 200F. Then immediately re-temper at last tempering temperature for one hour per inch of thickness.

Physical Properties
Modulus of Elasticity ...................................................................30 psi x 106
Density .............................................................................................0.283 lb/in3
Thermal Conductivity .........................................Approx. 18/19 BTU/hr./ft./F
Thermal Expansion

Temperature
Range
Coeff. of Thermal
Expansion
°F
°C
in/in/°Fx10-6
mm/mm/°Cx10-6
68-200
6.6
68-400
6.9
68-600
20-315
7.2
11.5
68-800
20-425
7.5
13.5
68-1000
20-540
7.7
13.9
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