Different Types of Welding Processes and Their Applications

There are countless different types of welding processes, from electrode-based arc welding to complex laser and plasma processes. However, there are four common types of welding that most fabricators should be aware of. The four main types of welding are:

• Gas Metal Arc Welding (GMAW/MIG)
• Gas Tungsten Arc Welding (GTAW/TIG)
• Shielded Metal Arc Welding (SMAW)
• Flux Cored Arc Welding (FCAW)

In this post, we’ll go over each process, how it works, and highlight some common applications for each type of welding.

Gas Metal Arc Welding (GMAW/MIG)

Gas metal arc welding (GMAW), also known as metal inert gas (MIG) welding, is a type of welding that falls under the broader category of arc welding. Arc welding simply refers to a welding process that uses an electrode to generate an arc of electricity that melts and joins the metal.

In GMAW/MIG welding, a wire electrode is heated as it is fed through the welding machine at a manually controlled rate. The wire is consumed into the weld as it is produced, so it acts as a filler metal. The weld must be shielded by an inert gas—typically argon blended with carbon dioxide, oxygen, and/or helium—to protect it from contaminants in the air.

GMAW/MIG is considered one of the easiest types of welding for beginners to learn, as it is fast and easy to control over thinner materials. For this reason, it’s commonly used to weld sheet metal—for example, for auto body parts. It’s also one of the most popular types of welding among hobbyists and home fabricators because of its forgiving nature and its versatility. This type of welding is effective on almost any material you’re likely to encounter, including stainless steel, carbon steel, aluminum, copper, and nickel.

While this type of welding is extremely versatile, it does have a couple of disadvantages to keep in mind. The equipment can be expensive, and there is the ongoing cost of shielding gas and electrodes. It’s also not the best method for welding materials thicker than about half an inch, and it is not suitable for vertical, overhead, or outdoor welding.

Gas Tungsten Arc Welding (GTAW/TIG)

Gas tungsten arc welding (GTAW), or tungsten inert gas (TIG) welding, is similar to GMAW/MIG in that it is a type of arc welding that uses an electrode to generate an electric current that heats and melts the metal. It also requires an externally delivered shielding gas to protect the weld. However, GTAW/TIG welding uses a non-consumable tungsten electrode rather than a consumable one, which leads to some significant differences in both the technique and results.

Because the electrode is not consumed, the filler has to be added separately if one is used. This makes TIG more challenging than MIG welding, as it requires both hands—one for the welding torch and one for the filler rod.

GTAW/TIG is considered one of the most difficult welding methods to master. Because there is only a tiny area between the arc and the area being welded, it takes a lot of precision and skill to perform. It is well worth the effort, though, for this type of welding produces clean, durable, and extremely strong welds. While less common among hobbyists, it is often used in industries like airframe manufacturing that require very strong, high-quality welds.

Aside from its steep learning curve, one of the downsides of this type of welding is its cost. Like GMAW/MIG, it requires shielding gas, and because it’s a much slower process, the welding cost is higher. While it’s a more precise technique, it’s most effective on materials that aren’t more than a few millimeters thick.

Shielded Metal Arc Welding (SMAW)

Shielded metal arc welding (SMAW), also known as stick welding, uses a consumable electrode much like GMAW or MIG welding. However, this type of welding is even simpler because it doesn’t require a separate shielding gas.

In stick welding, the electrode is in the form of a stick coated in flux. When the electrode is consumed, the flux disintegrates and releases gases that protect the weld—so there’s no need for an external shielding gas.

Because of its simplicity and low cost, stick welding tends to be the most popular type of welding among home welders. It’s also the go-to welding technique for outdoor welding where wind and rain proscribe the use of shielding gas, and it even works well on dirty and rusty materials. Stick welding is common in both home shops and industrial applications like construction, shipbuilding, and repairing pipelines.

The downside of stick welding is that it doesn’t typically produce the best quality welds. Compared to other types of welding, stick welds are more prone to weld problems like porosity and cracking and are less durable.

Flux Cored Arc Welding (FCAW)

Flux cored arc welding (FCAW) is another welding technique that, like GMAW/MIG, uses a continuously fed wire electrode. However, FCAW can either use a shielding gas or an electrode with flux agents that produce shielding gases when consumed.

This is another one of the least expensive and easiest types of welding to learn. Like MIG or stick welding, it’s a great technique for beginners to start with while being useful for many applications.

Like stick welding, FCAW can be performed outdoors when shielding gas is not used. It’s fast, portable, and produces good quality welds, making it valuable for construction projects and other outdoor welding work. It is also much better at welding thick materials than the other types of welding we’ve discussed.

FCAW does have one important downside; while it is very effective for welding ferrous materials like carbon steel, stainless steel, and cast iron, it cannot be used to weld nonferrous materials like aluminum.

Weld-Ready Materials, Cut to Size by Your Local Metal Supplier

Whether you’re a hobbyist, an independent professional, or the manager of an entire plant full of welders, material matters. No matter what type of welding you’re doing, quality welds come from quality metal—so be thoughtful about where you source your material.

At Industrial Metal Service, we have more than two decades of experience offering a wide range of new and verified remnant metal—including stainless steel, aluminum, titanium, and more—to our customers in the San Francisco Bay Area and beyond. We’ve earned our reputation as a reliable and trustworthy metal supplier, and we want to make sure you have the best materials for all types of welding and other fabrication processes.