As a plasma gas almost exclusively argon is used. Depending on the type of torch, and the chosen intensity of the welding current, about 0.1 to 6 l/min of plasma gas are needed.

As shielding gas, argon or Ar/H2 – or Ar/He – gas mixtures are used. Adding hydrogen or helium increases the seam depth and the welding speed can be increased by up to 20 %. Depending on the type of torch, between 3 and 20 l/min of shielding gas are needed.

To protect the root of the seam, the usual forming gases are used (Ar, gas mixtures of Ar/N2 and Ar/H2).