... WELDER The characteristic of DC inverter TIG/MMA welder: 1.Adopts advanced V-MOS inverter technology, operating frequency of 100KHZ ... frequency, concentrative arc makes the best welding line and soldering quality, very suitable for welding line with special rwquirements. 3. ... Easy to operate by TIG/MMA welding. suitable for welding stainless steel, mild steel, steel alloy, cooper, etc ...