Which Shielding Gas/Gases Should I Use for TIG Welding?

Pure argon is the most common shielding gas for TIG welding as it will cope with all common materials. For some specialized and automated processes, helium and argon-helium mixes are sometimes used. Argon-mix gases and CO2 as used in MIG welding cannot be used with TIG; the CO2 in the mix is an active gas and will destroy the tungsten electrode as soon as an arc is struck.