... control 4:simens igbt high frequency heating quenching furnace for auto parts shaft Hardening/quenching categories:1. All kinds of gears ... axle, leaf springs, fork, valve, rocker, ball stud and other auto parts quenching.3. All kinds of engine parts, gear parts ... hardened surface;4 bed machine tool of machine tool industry guide of quenching (lathe, milling machine, planer, punch, etc.)5. All ...