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 - 1850°F-1950°F 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
300°F - 1 hour - R/C 60
500°F - 1 hour - R/C 57
800°F - 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 - 1850°F-1958°F max
Hold for 30 minutes
Quench in warm oil

Hardening & Tempering Information
572°F - 1 hour - R/C 56-57
932°F - 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 1625-1650°F and soak thoroughly (5 hours minimum at temperature)
  
• Furnace cool 50°F per hour to 1100°F 
  
• Continue furnace cool (Furnace may be shut off) to 800°F 
  
• Parts may be air cooled from 800°F to room temperature 
  
• Resulting hardness Brinell 269 maximum
  

Hardening & Tempering Information

• Preheat 1500°F
  
• Austenitize at 2050°F in salt*
  
• Oil quench to room temperature or salt quench at 1050°F, then air cool to room temperature.
  
• Stress relieve at 300°F - one hour - air cool
  
• Refrigerate at -100°F - equalize - air warm
  
• Double temper at 975°F - 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.