TIG welding (tungsten argon arc welding) is a welding method with pure Ar as the shielding gas and tungsten as the electrode. TIG wire to a certain length (usually LM) straight strip supply. An inert gas arc welding with pure tungsten or activated tungsten (thorium tungsten, cerium tungsten, zirconium tungsten, lanthanum，tungsten) as an unmelted electrode, in which the metal is melted by an arc between the tungsten electrode and the workpiece to form a weld. 

In the welding process tungsten is extremely unfused and acts only as an electrode. At the same time, argon or helium gas is sent into the nozzle of the welding torch for protection. Additional metals can be added as needed. In the international known as TIG welding. The main advantage of TIG welding is that it can weld a wide range of materials. Including the thickness of 0.6mm or above of the workpiece, the material includes alloy steel, aluminum, magnesium, copper and its alloy, gray cast iron, ordinary dry, various bronze, nickel, silver, titanium, and lead. The main application area is to weld thin and medium thickness workpieces, used as solder beads on thicker sections. 

MIG welding (MG gas shielded arc welding) is MG inert gas shielded welding, with Ar and other inert gas as the main shielding gas, including pure Ar or Ar gas mixed with a small amount of active gas (such as O2 below 2% or below 5% CO2 gas) welding method of MG arc welding. MIG wire is supplied in coil or disk form. This welding method uses the burning arc between the continuous welding wire and the workpiece as the heat source, and the welding arc is protected by the gas ejected from the welding torch nozzle.

The shielding gases commonly used in MGA arc welding are argon, helium, carbon dioxide or a mixture of these gases. When argon or helium gas is the shielding gas, it is called molten inert gas shielded arc welding (known as MIG welding in the world). When the mixture of inert gas and oxidizing gas (oxygen, carbon dioxide) is used as the shielding gas, or when the mixture of carbon dioxide gas or carbon dioxide + oxygen is used as the shielding gas, it is collectively referred to as the molten extremely active gas shielded arc welding (known as MAG welding in the world). The main advantages of MGA arc welding are that it can be easily welded in various positions, and it also has the advantages of faster welding speed and higher deposition rate. It is suitable for welding most major metals, including carbon steel and alloy steel. FGAS arc welding is suitable for stainless steel, aluminum, magnesium, copper, titanium, pickax, and nickel alloys. Arc spot welding can also be carried out by this welding method.