... and Ductile cast iron.4.Welding, Welding head, lathe tool, reamer, milling cutter, drill bits, and stainless steel bottom of ... application of high-frequency 50-100 KHZ20-30mm above the tool to apply high-frequency 10-50 KHZ, super audio 30 ... mm above the tool applies to 1-8 KHZ IF 5,Metal meltingSpecialized in ...