The process employs three salts as follows:

FRANK 660 / FRANK REGENERATOR for Pre Heating; FRANK 970 / FRANK HSX for heating to the hardening temperature and FRANK 540, FRANK 495 for quenching and subsequent tempering. This process eliminates scaling and decarburization reduces the risk of cracking and distortion and enables a high output for relatively small furnaces. Work is heat-treated in four main steps.

• Pre Heat in the air to 350-400°C
• Soak in FRANK 660/FRANK REGENERATOR at 800-850°C
• Heat to the hardening temperature in FRANK 970 OR FRANK HSX.
• Quench in FRANK 540 or FRANK 495 and in air cool.
• Temper in FRANK 540 or FRANK 495 and air cool. It is usual to temper twice at the same temperature with an air cool between. All tools are first heated in air to 350-400°C, then immersed in FRANK 660 / FRANK REGENERATOR and soaked for 5-15 minutes after attaining 800-850°C. They are then transferred to the FRANK 970 or FRANK HSX baths.