MIG stands for Metal Inert Gas welding, often called Wire-feed. It is also referred to as GMAW (Gas Metal Arc Welding). The "Metal" refers to the wire which is what is used to start the arc. It is shielded by inert gas and the feeding wire also acts as the filler rod. A semi-automatic process, it is fairly easy to learn and use (Check out our Mig Welding Rod Ovens).
Those who practice mig welding are often referred to as wire-feed welders. It is used on all thicknesses of steels, aluminium, nickel, stainless steels etc. It is most typically utilized in commercial fabrication settings where continuous welding is desired, and where environmental conditions, joint preparation, and materials can be controlled.
The mig weld process consists of a DC arc burning between a thin bare metal wire electrode and the workpiece. The arc and weld area are enveloped in a protective gas shield. The wire electrode is fed from a spool, through a welding torch which is connected to the positive terminal into the weld zone.
Mig welding is the most widely used process in the world today. It is a versatile method which offers a lot of advantages. The technique is easy to use and there is no need for slag-cleaning. Another advantage is the extremely high productivity that mig welding makes possible.
Highly flexible and adaptive, MIG welding is used when you wish to obtain high productivity and high quality results. This process is also used for manual (semi-automatic) welding or automated/robotized installations on low alloy carbon steels, high alloy stainless steels or non-ferrous alloys such as aluminum or copper.
MIG welding is required by law and by insurance companies in many localities for structural repair of automotive frames. MIG is also much easier to learn and faster to weld. For doing other types of welding, like sheet metal, it can be a matter of personal preference. For an auto body repair shop or a novice welder, MIG welding is a good, practical process.