TECHNICAL INFO
440C Stainless
Typical Analysis
C 1.03  Mn .44  P.025  S.001  Si .65  Ni .30  Cr 16.68  Mo .50  Cu .16
Hardness
R/B 92-95

Heat Treating Information
Initial Quench Temperature - 1850F-1950F max
Hold for 30-45 minutes
Quench in warm oil or air cool
Do not overheat (too much time or too high temperature)

Hardening & Tempering Information
300F - 1 hour - R/C 60
500F - 1 hour - R/C 57
800F - 1 hour - R/C 56

ATS-34 Stainless
Typical Analysis
C 1.02  Mn .40  P.025  S.002  Si .24  Cr 13.66  Mo 3.52
Hardness
R/B 97

Heat Treating Information
Initial Quench Temperature - 1850F-1958F max
Hold for 30 minutes
Quench in warm oil

Hardening & Tempering Information
572F - 1 hour - R/C 56-57
932F - 1 hour - R/C 58-59

BG-42 Stainless


Typical Analysis
C 1.15  Mn .50  Si .30  Cr 14.50  Mo 4.00  V 1.20

Heat Treating

  • Heat slowly to 1625-1650F and soak thoroughly (5 hours minimum at temperature)
  • Furnace cool 50F per hour to 1100F 
  • Continue furnace cool (Furnace may be shut off) to 800F 
  • Parts may be air cooled from 800F to room temperature 
  • Resulting hardness Brinell 269 maximum

Hardening & Tempering Information


  • Preheat 1500F
  • Austenitize at 2050F in salt*
  • Oil quench to room temperature or salt quench at 1050F, then air cool to room temperature.
  • Stress relieve at 300F - one hour - air cool
  • Refrigerate at -100F - equalize - air warm
  • Double temper at 975F - 2 hours each - air cool
  • Resulting hardness Rockwell C61-64

*Time is 30 minutes at temperature.  BG-42 requires a longer cycle than normally associated with high speed steel.

The refrigeration cycle is incorporated into the treatment in order to assist in the transformation of retained austenite.  To minimize the danger of cracking, the stress relief has been installed at no sacrifice of subsequent hardness response.  Multiple tempering , perhaps four times, is recommended when minimum retained austenite is essential.