MIG vs TIG: What Is The Difference Between TIG And MIG Welding?

‘TIG’ stands for ‘Tungsten Inert Gas’ welding, whereas ‘MIG’ stands for ‘Metal Inert Gas’ welding.

You might also come across TIG being referred to by the acronym ‘GTAW’ (Gas Tungsten Arc Welding) – the process is exactly the same in both cases. It uses a non-consumable electrode and a shielding gas to make and protect the joint during the welding process.

MIG welding – also known as GMAW (Gas Metal Arc Welding) or MAG (Metal Active Gas welding) – uses a different type of electrode. In this case, the electrode is consumable, so it is used up while welding and needs to be replaced when it runs out. Like TIG, MIG welding also uses a shielding gas to protect the weld pool from potentially damaging atmospheric gases.

As a result, the main difference between MIG and TIG welding is that MIG uses a wire which constantly feeds through the welding machine, while TIG uses long rods which have to be held separately and fed into the weld puddle. As TIG requires both of the welder’s hands, it’s much easier to get to grips with MIG.

TIG is a fairly technical process to learn which requires a refined technique, holding the torch at a specific angle, and a great deal of care. This means that although the results might be cleaner and more visually appealing, it can’t be rushed, so it isn’t ideal if you need to do a high volume of welding. MIG is a better choice for larger scale production as it doesn’t need to be quite as accurate to be strong.

TIG is best suited for thin metals such as aluminium, while MIG can be used with both thin metals (such as on automotive jobs) and thicker plates.

With regards to the shielding gas, it is common for TIG welding to use a mixture of helium and argon to protect the weld. With MIG the composition of the shielding gas is slightly different, as it’s usually made up of either straight carbon dioxide or carbon dioxide mixed with argon. Shielded metal arc welding (SMAW) is an entirely different process altogether, as this uses a coated electrode to provide all the necessary protection.