... 380V,30-80KHZ 4. Metal superficial heating is perfect This high frequency induction heating machine A. Heating (hot forging, hot fitting and smelting ... with the help of punch press, forging machine or other equipments, for instances, hot extrusion of watch case, watch flan ... of stainless steel flat base, aluminum sheet and tubular electric heating elements of various forms. D. Annealing (tempering and ...