There are three main welding types:
- MIG – Metal Inert Gas Welding (GMAW)
- TIG – Gas Tungsten Arc Welding (GTAW)
- Stick – Shielded Metal Arc Welding (SMAW)
Each welding type is used for different reasons and has different finishes.
MIG- Metal Inert Gas Welding
MIG welding is one of the most common types of welding. This type of welding uses a continuous wire electrode that is heated and fed into a weld pool from the welding gun. The wire serves as a heat source and a filler metal. This creates a join where the two base materials are melted together. The gun is also feeding a shielding gas with the electrode to seal the weld from the air. The shielding gas depends on the metal being welded and the weld being done. Shielding gas has a large effect on the stability of the arc and is an important part of every weld. MIG welding first gained popularity in the UK in the 1950s for welding aluminum using argon for the shielding gas. It then spread to other countries and became a popular choice for welding carbon steel.
The technique is versatile in that it can be used for thin and thick components. With the fire being continuously fed this is a technique that is not only effective but is highly productive. The welder is in control of the speed of the weld and the position however the arc length and wire feed rate are done through the power source.
The McMahan team uses MIG welding on most of our stainless steel projects. We can do 100% penetration and ensure clean quality welds for food-grade products. Our shop has suitcase welders that are MIG welding machines that run flex-cored wire. This is a wire that has gas to create the welding shield. This saves us time when we are doing on-site welds.
MIG welding is used in a range of industries. MIG welding accounts for more than 50% of welded metal.
TIG- Gas Tungsten Arc Welding
TIG welding uses a tungsten electrode. This form of welding uses a gas shield to protect the weld pool rather than slag. It replaced manual metal arc welding in the 1940s. TIG changed the game in what metals could be used for structural applications. It added aluminum as a possibility that had not yet been widely used at the time. It was first mainly used in the aircraft industry to weld magnesium. A pointed tungsten electrode creates a strong arc. Tungsten is a tougher metal that does not dissolve or burn off. A thin wire filler is fed by hand into the pool where it melts. TIG welding is slower than some other processes but in many ways is similar to other arc welding types. The electrode type and the equipment needed distinguish it from other welding processes.
This welding process can be used on a wider range of metals than any of the other welding types. It is still widely used in the aircraft industry and is also used for spacecraft. This form of welding is common for auto shops but is also a favorite of sculpture artists due to the high quality of the final weld.
Stick- Shielded Metal Arc Welding
This form of welding is one of the oldest forms of welding. The process was patented in 1890 by Charles Coffin. SMAW is a manual welding process that is still one of the most commonly used. It can be used for all positions and on all ferrous metals. While it is common it also requires practice and skill to create quality welds with this welding process.
SMAW is also known as stick welding. A metal rod coated in flux is used to form the weld, thus the term “stick”. Electricity hits the base metal after flowing through the rod. The flux forms the gas shield and is part of what makes this weld so versatile in where it can be used. It uses the heat of the arc to melt a consumable electrode and base metal. The metal forms on the end of the electrode which transfers from the arc into the weld pool. The filler is deposited as the electrode is consumed. This welding technique creates a circuit between the electrode and the base. This requires a ground clamp to ground the circuit that is created. The downfall is that this form of welding creates slag that must be removed.
SMAW is used often in construction, pipelines, shipbuilding, farm machinery, and structural welding.