FRANK HSX is used for heating high-speed steels and hot work steels to the appropriate hardening temperature. It is used alone to prepare the initial melt and for topping up to maintain the bath level.

It contains its own rectifiers to keep the bath in non-decarburising condition. Each day the bottom of the pot must be dredged to remove sludge and fresh FRANK HSX salt equivalent to 10% of the bath weight must be added daily. After treatment in FRANK HSX the tools are quenched in FRANK 540, FRANK 495 or oil. Subsequently, the tools are tempered using FRANK 540/ 495.