This equipment adopts uprated self-excited vacuum tube oscillator. Through it transform the 50Hz power current into different frequency current. This current can produce a powerful magnetic file in the quenching sensors. The metal workpiece will speedy heating when the electromagnetic field produce eddy current and magnetic leaking loss, the surface of metal can reach high temperature and heating in a few seconds. It widely use in heating treatment. Vacuum tube high frequency of ultrahigh frequency at quenching high precision workpiece can keep the workpiece not out of shape,hardening layer ultra-thin and can not be replaced by IGBT ultra-audio frequency solid state HF equipment.