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The Shielded Metal Arc Welding (SMAW) process is the oldest and most versatile of the welding processes. It is a manual process in which the welder uses a consumable metal electrode coated in flux to create the weld. An electric current, either Direct Current (DC) or Alternating Current (AC) from a welding power supply is used to create an electic arc between the electrode and the metals to be joined. The electrode disintegrates adding metal to the weld pool and the flux coating burns off providing shielding gas for the weld pool, and a slag coating. Both of which protect the weld from harmful atmospheric contamination.

GMAW Gas Metal Arc Welding (GMAW) is sometimes referred to by its subtypes Metal Inert Gas (MIG) and Metal Active Gas (MAG). This process is when an electric arc forms between a consumable wire electrode and the work pieces. The work pieces melt from the heat of the arc and are joined together with added filler metal from the wire. Along with the electrode wire, inert shielding gas feeds through the GMAW gun. This gas protects the molten metal from the air. There are four methods of metal transfer in GMAW. They are called short circuiting, globular, spray and pulsed spray. Each method has its own unique purposes and limitations.

GTAW Gas Tungsten Arc Welding (GTAW) also known by Tungsten Inert Gas (TIG) or HeliArc is a manual or semi-automatic welding process which uses a non- consumable tungsten electrode to produce an electric arc. An inert shielding gas is used to protect the weld pool from the atmosphere. Most often filler metal is added to the weld manually at the point of the weld pool, although some welds known as autogenous welds do not require it. GTAW requires a constant current welding power supply which produces an arc through a column of ionized gas and metal vapors known as plasma.

GTAW is commonly used to weld thin sections of stainless steel, aluminum, magnesium, and copper alloys. The process grants the welder greater control over the weld pool than competing processes such as GMAW and SMAW allowing for stronger, higher quality welds. GTAW is comparatively more complex and difficult to master than its competing processes, calling for high levels of skill to produce consistant high quality welds. It is also signifigantly slower than other processes. A related process called Plasma Arc Welding (PAW) uses a slightly different torch design to produce a more focused welding arc, and as a result is generally automated.