The “TIG” in TIG welding stands for Tungsten Inert Gas. But before it was named so, it was called “Heliarc” because of the helium that was dominantly used when the process was invented. But then someone discovered that argon worked better and so it was called “TIG” because inert gas could refer to either helium or argon.

Soon later, it was discovered that small additions of hydrogen worked well for some metals. The word “inert” no longer applied to the new discovery. Thus, the technical term for what used to be called TIG and Heliarc is now “GTAW” or Gas Tungsten Arc Welding.

TIG welding is similar to gas welding as far as welding technique is concerned. However, compare to other arc welding processes TIG welding is difficult to use as it requires both hands with one in the filler rod and the torch in the other. Oftentimes, a foot pedal amperage control is also used which makes it more difficult.

A TIG torch can either be water or air cooled and is designed to provide shielding gas and welding current through a tungsten electrode. A ceramic nozzle directs the shielding gas to the weld puddle and internal copper parts like the collet and the collet body holds the electrode in place. The tungsten electrode is sharpened for applications where the arc needs to be pinpointed for very low amperage.

The heat that melts the metal and makes the weld puddle comes from the arc that is created between the tungsten and electrode and the work piece. The arc is shielded either by argon or helium, or the mixture of both. Sometimes for certain alloys, hydrogen is added in small percentage to improve the way the puddle flows. The arc is very smooth, quiet and clean when DC current is used. When the TIG welding machine is set on Alternating current, it is slightly noisier but still clean and smooth.

Here is a list of some popular metals that can be welded using the TIG welding process: Carbon and low alloy steels like 1010 carbon and 4130 chromoly steels; 301, 321 and 17-7ph stainless steels; inconel 718 Nickel alloy and X Hastelloy; Aluminim alloy like 6061 and 5052; az31b Magnesium alloys; 6a14v Titanium alloys and those that are commercially pure; Stellite 6b and 1605 Cobalt alloys; copper alloys like Nibral bronze and pure copper and a whole lot more.

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