Gas Metal Arc Welding (GMAW) is sometimes referred to by its subtypes Metal Inert Gas (MIG) and Metal Active Gas (MAG). This process is when an electric arc forms between a consumable wire electrode and the work pieces. The work pieces melt from the heat of the arc and are joined together with added filler metal from the wire. Along with the electrode wire, inert shielding gas feeds through the GMAW gun. This gas protects the molten metal from the air.

The GMAW process can be automatic or semi-automatic. A constant voltage, direct current (DC) power supply is most commonly used with GMAW, although constant current, alternating current (AC) can be used as well. There are four methods of metal transfer in GMAW. They are called short circuiting, globular, spray and pulsed spray. Each method has its own unique purposes and limitations.

A Drawing of the GMAW welding process at the Weld pool









A Drawing of typical equipment used in the GMAW Process.