GMAW, GTAW, and SMAW Welding: What You Need to Know

For centuries, the primary method of joining two metals together was called “forge welding.” This relatively primitive method of welding involved heating two pieces of metal until they were extremely hot, then forcing them together using pressure – such as from a hammer – causing deformation of the weld surfaces.

In turn, this bonded the metal together permanently at a molecular level. While this remains an effective method of joining metal, it’s definitely not the most common today – thanks to the rise of safer, quicker, and better welding methods.

Curious to learn more about welding, and the common methods that are used today? You’re in the right place. In this article, we’ll discuss three of the most commonly used types of welding that are common today – SMAW, GTAW, and GMAW welding.

Different Types of Welding

Not all welding methods are built alike. Whether you’re an experienced welding professional and want to be able to explain each different welding method to a customer, you’re a hobbyist who is getting started with a welder, or you are just curious about getting more information, we’ve put together a brief overview of each type of welding, so that even a layman can understand the differences between each welding style, and which one may be right for a particular job.

So let’s get started and discuss SMAW, GTAW, and GMAW welding now, and go over the attributes, defining features, and common applications of each.

SMAW Welding

SMAW is short for “Shielded Metal Arc Welding.” Informally, it’s also sometimes called “stick” welding. This is because it uses an electrode, which is shaped like a stick. During the welding process, this electrode is melted together with the metal that is being welded.

This creates what’s known as a “weld pool.” This weld pool must be carried along the joint in a consistent manner to create a stronghold and join the metal together permanently. Because the rod-shaped electrode is consumed while welding, it must be changed regularly, and may even need to be swapped during a welding job.

SMAW welding provides the strongest hold out of any welding method and is good for most construction and industrial applications, as it can be used on almost all metals of varying thicknesses.

Another benefit of SMAW welding is that it can be done in just about any type of weather, as long as the metal is above 0 degrees Fahrenheit, and the welded material is kept safe from rain, snow and blowing sand.

However, it’s not ideal for very thin sheet metal, and it usually takes a much longer time to weld objects compared to GTAW and GMAW, because the electrode must be regularly swapped. In addition, these frequent stops and starts can result in weld defects, in some cases.

GTAW (Tungsten Inert Gas) Welding

GTAW is short for Gas Tungsten Arc Welding and is also sometimes called TIG (Tungsten Inert Gas) welding. This type of welding uses a tungsten electrode to deliver the electric arc. The tungsten can withstand extremely high temperatures, so it does not melt, and it is not consumable, unlike SMAW and GMAW.

This means that a “filler metal” must be used to melt and create the weld pool which allows the metals to be joined together. The proper fill metal depends on the material, thickness, and a number of other factors.

It’s often considered to be the most difficult welding method to master. However, when done properly, GTAW can create extremely clean, pleasing-looking welds, and the welder has unparalleled control over the weld, making it ideal for applications where the weld will be visible and must be clean and appealing.

It also does not produce sparks, fumes, smoke, or slag, and can be used on metals of any thickness. It’s often used in shipbuilding, automotive, and aerospace applications.

GMAW (Metal Inert Gas) Welding

Gas Metal Arc Welding (GMAW) is also sometimes known as Metal Inert Gas (MIG) welding, though MIG is actually a specific subtype of GMAW.

This method of welding uses a long spool of wire-fed consumable electrode, which melts together with the metal to create a weld pool. Because the electrode is always melting and delivering a constant stream of weld, this helps prevent contamination and messy welding. A separate tank of gas helps shield and prevent contamination of the weld site, hence the term “gas metal arc welding.)

This method of welding is typically considered to be the easiest to learn, as it’s easy to control the speed of the wire electrode, and you do not have to stop to swap it out regularly, unlike SMAW welding, and you don’t need to feed a filler metal, unlike GTAW welding.

This also means that GMAW is one of the most efficient methods of welding. It can be used to quickly join a number of metal parts with very minimal downtime. However, GMAW equipment is quite expensive, compared to other types of welding equipment, and the larger size of a GMAW welding “gun” can make it difficult to work in tight spaces.
GMAW is typically used in a wide variety of commercial applications, mostly on nonferrous metals like aluminum, though it is sometimes also used for some types of steel, in some cases. This method of welding is commonly used in the automotive, plumbing, manufacturing, and construction industries, and is also the most common method used for underwater welding.

Knowing Which One to Use

There are many different types of welding that may be right for a particular project, and it’s not always easy to understand which one is right for you. It depends on a number of factors – such as the type of metal being welded, the thickness of the metal, the desired strength and appearance of the weld, and much more.

If you’re still not sure which welding technique is the best for your orders and you would like more information, please send us a message online, or give us a call at 423-624-3300. We’re always happy to explain more about welding and help you understand this subject in further detail.

 

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