GMAW Wires : Metal Arc Welding (GMAW) is a welding process which joins metals by heating the metals to their melting point with an electric arc. The arc is between a continuous, consumable electrode wire and the metal being welded. The arc is shielded from contaminants in the atmosphere by a shielding gas. The essential feature of the process is the small diameter electrode wire, which is fed continuously into the arc from a coil.