TIG (Tungsten Inert Gas) welding or Gas-Shielded Tungsten Arc Welding (GTAW) is a process, which uses a non-consumable solid tungsten electrode. The electrode, the arc and the area surrounding the molten weld puddle are protected from the atmosphere by an inert gas shield. If a filler metal is necessary, it is added to the leading edge of the molten puddle.

TIG welding produces exceptionally clean, high quality welds. As no slag is produced, the chance of slag inclusions in the weld metal is eliminated and the finished weld requires virtually no cleaning. TIG welding may be used for welding almost all metals and the process lends itself to both manual and automatic operation. TIG welding is most extensively used for welding aluminium and stainless steel alloys where weld integrity is of the utmost importance. It is widely used for high quality joints in the nuclear, chemical,aircraft and food industries.