Gas tungsten arc welding, also known as TIG welding, is a welding process where a non-consumable tungsten electrode produces an arc between the electrode and the base material being welded. TIG welding uses a shielding gas to protect the weld area from atmospheric contamination and uses a non-consumable tungsten electrode to produce the weld. Common TIG welding machines allow control of welding current, polarity, and gas flow to produce quality welds on a variety of joint configurations.