While there are several types of welding processes, such as – Arc welding, Gas welding, Resistance welding, Solid-state welding, Laser beam welding, Electron beam welding, Atomic hydrogen welding, Submerged arc welding, Plasma arc welding, Friction welding, Ultrasonic welding, and Explosive welding, the four main types of welding are:

1. Gas Metal Arc Welding (GMAW/MIG)

2. Gas Tungsten Arc Welding (GTAW/TIG)

3. Shielded Metal Arc Welding (SMAW)

4. Flux Cored Arc Welding (FCAW)

Gas Metal Arc Welding (GMAW/MIG)

Also known as Metal Inert Gas or MIG welding, this process uses a thin wire as an electrode. The wire heats up as it is fed through the welding instrument and towards the welding site. Shielding gas must be used to protect the weld from contaminants in the air.

Typically, this comes in the form of carbon dioxide, oxygen, argon, or helium. This method is often used to work on metals such as stainless steel, copper, nickel, carbon steel, aluminum, and more. This one is most popular among all the welding processes across the construction and automotive industries.

GMAW is believed to be an easier welding technique to learn, making it a great area of focus for beginning welders. It also calls for minimal cleanup and offers high welding speeds and better control over thinner materials.

Some downsides associated with this welding process revolve around the costs of getting shielding gas and an inability to weld thicker metals or perform vertical or overhead welding.

Gas Tungsten Arc Welding (GTAW/TIG)

This type of welding process, also known as Tungsten Inert Gas or TIG welding, is commonly used to weld together thin and non-ferrous materials like aluminum, copper, lead, or nickel. It’s commonly applied to bicycle or aircraft manufacturing.

Unlike other types of welding processes, TIG welding uses a non-consumable tungsten electrode to produce the weld. You will still need an external gas supply, usually argon or a mix of argon and helium.

This is considered one of the most difficult welding methods to master and produces the most high-quality welds. Because there is only a tiny area between the arc and the area being welded, it takes enormous precision and skill to complete. Welds born of this method are known to be extremely strong.

Shielded Metal Arc Welding (SMAW)

This type of arc welding process relies on a manual technique using a consumable electrode coated in flux. This method tends to be most popular among home-shop welders. This process is also more informally known as stick welding.

The nickname references the electrode used to weld the metal, which comes in the form of a “stick.” Because SMAW requires minimal equipment, it’s one of the most low-cost processes. This type of welding does not require shielding gas and can be performed outdoors in the wind or rain. It also works well on dirt and rusty materials. That said, downsides do exist.

Stick welds don’t typically produce the best quality products. They are prone to porosity, cracks, and shallow penetration. In general, stick welds are less durable than other types of welding.

Flux Cored Arc Welding (FCAW)

Similar to MIG welding, FCAW revolves around a continuous wire feed process. There are two separate processes associated with FCAW. One involves the use of shielding gas, while the other relies on self-shielding agents produced when fluxing agents decompose within the wire.

This type of welding is known for being inexpensive and easy to learn. Much like the MIG welding process, it’s a great way for beginning welders to kick off their careers in the field.

It also allows welders to work outdoors (windy conditions won’t affect the weld). The semi-automatic arc provides high welding speed and portability, making it a popular process to employ on construction projects.