TIG (tungsten inert gas) welders supply power to compatible TIG torches to create an arc between a tungsten electrode held in the torches and a metal workpiece. The arc melts and fuses the workpiece material to form a weld. The maximum amperage rating of the welder should be less than the maximum amperage rating for the torch. Also known as gas tungsten arc welding (GTAW), TIG welding creates clean, precise welds on a wide range of materials. It is ideal for welding thin materials and surfaces that will be visible.