Metal Inert Gas or MIG welding is a welding process which uses an inert gas such as argon to shield the arc to prevent oxidation of the molten metal. The filler wire is automatically fed to the welding contact tip at a controlled rate. MIG welding allows continuous, high quality welds on a variety of materials such as plate steels, sheet metal, aluminium and stainless steel. The process gives the welder excellent control over the depth and size of the heat affected zone and molten pool. Little or no slag is produced with low splatter meaning little or no post finishing is required.
MIG welding also lends itself readily to automated welding processes using robots or dedicated machines.
These days the majority of steel and aluminium fabrication uses MIG welding as its primary welding process. Examples of automated MIG welding applications are commonly found in auto assembly plants.