Plasma Arc Welding (PAW) is a special form of gas tungsten arc welding in which constricted plasma arc is directed at the weld area. In PAW, a tungsten electrode is contained in a specially designed nozzle that focuses a high-velocity stream of inert gas (argon or argon-hydrogen mixtures) into the region of the arc to form a high velocity, intensely hot plasma arc stream.

Temperatures in plasma arc welding attain 28000ºC or greater, hot enough to melt any known metal.

Advantages of PAW are good arc stability, better penetration control than most other arc welding process, high travel speed and excellent weld quality.