Preheat: Heat material to 1400°F (760°C) Equalize.
Austenitize: For Max Toughness heat to 1950°F – 1975°F. Hold that temperature for 45-60 minutes. For Max Edge Retention – 2050°F, hold time at temperature 45-60 minutes.
Quench: Oil or positive pressure (4 bar minimum) to below 125°F (50°C), or salt quench to about 1000°F (540°C), then air cool to below 125°F (50°C). Salt bath treatment, if practical, will ensure the maximum attainable toughness for a given hardening treatment.
Temper: Three times at 950°F for Rockwell 60-61 – 2 hours minimum each time. Three times at 1000°F -1100°F for Rockwell 58-59 – 2 hours minimum each time.
