Weman , p NUMBER@1 Gas tungsten arc welding -LRB- GTAW -RRB- , or tungsten inert gas -LRB- TIG -RRB- welding -LRB- also sometimes erroneously referred to as heliarc welding -RRB- , is a manual welding process that uses a nonconsumable tungsten electrode , an inert or semi-inert gas mixture , and a separate filler material .

Gas tungsten arc welding -LRB- GTAW -RRB- : GTAW is also known as TIG -LRB- tungsten inert gas welding -RRB- .
