With MIG (Metal Inert Gas) or MAG (Metal Active Gas) welding also called Gas- Shielded Metal Arc Welding (GMAW) an arc is maintained between a continuous solid wire electrode and the work piece. The arc and weld pool are shielded by a stream of inert or active gas. The process is suitable for most materials and filler wires are available for a wide range of metals.

MIG/MAG welding is inherently more productive than MMA, where productivity losses occur each time a

welder stops to replace a consumed electrode. Material losses also result from MMA welding when the stub of each electrode is thrown away. For every kilogram of coated stick electrode purchased, about 65 per cent becomes part of the weld (the rest being discarded). The use of solid wire and flux cored wire has increased this efficiency to 80-95 per cent. MIG/MAG welding is a versatile process, which can deposit weld metal at a very high rate and in all positions. The process is widely used on light to medium gauge steel fabrications and on aluminium alloy structures particularly where high-rate manual operator production is required. The introduction of flux cored wires is finding increased application in heavy steel structuresaircraft and food industries