Welding has come a long way since humankind first discovered how to use heat to fuse metals back in 3,000 BC.
Today, several welding types are put to use in many different industries and applications.
Welding involves the application of high heat and pressure, along with a filler metal, to create a weld pool between two metals. Once the pool cools, a strong joint (or weld) is made.
The outcome is always the same, but the methods and equipment used to create the joint varies.
Are you considering a career in welding? No matter where you end up in this field, you’ll need a diverse knowledge of the types of welding, along with a lot of hands-on experience well before you ever enter the job field.
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The most popular welding types are only the tip of the iceberg. In our ultimate welding guide below, we’ll walk you through the various types of welding, what they are used for and what sets the different welding processes apart.
Here are the different types of welding you’ll be learning about.
- Shielded Metal ARC Welding (SMAW)
- Gas Metal Arc Welding (GMAW)
- Flux-Cored Arc Welding
- Plasma Arc Welding (PAW)
- Gas Tungsten Arc Welding (GTAW) aka TIG
Shielded Metal ARC Welding (SMAW)
The simplicity of equipment and versatility are key factors in the longevity of SMAW. [i]
In SMAW, the arc is struck when electricity passes through the coated electrode tip and touches the base metal. The arc is maintained once the electrode is withdrawn.
The heat melts the coating, which becomes a shielding gas. The remainder of the metal electrode melts into the weld pool, becoming part of the weld when the alloy solidifies.
SMAW is commonly used in several industries:
- Farm machinery
- Underwater welding
SMAW has several advantages:
- Basic, portable equipment
- Can be used for a range of metal types of various thicknesses
- Good for working outdoors[ii]
Gas Metal Arc Welding (GMAW)
This type of welding is appealing to contractors as a reliable and cost-saving welding method.
GMAW is considered a semi-automatic welding method because the electrode, a metal wire, is fed continuously through a welding gun into the weld pool. It protects the arc from atmospheric contaminants with a shielding gas, which is also delivered through the gun.[iii]
GMAW can really speed things up on the jobsite, reducing overhead costs by up to 25 percent![iv]
Gas Metal Arc Welding is commonly used in the following areas:
- Pipe welding/pipe joints
- Automotive production and maintenance
- Railroad tracks
- Underwater welding
Welders choose GMAW for a variety of reasons:
- It can be semi- or fully automated.
- It’s good for thin metals or thick joints.
- Minimal cleanup afterward is required, and it’s not prone to chipping.
- Flexibility: can weld in any position
- Cost effective, fast welding process
- Minimal waste because the electrode is consumable
Flux-Cored Arc Welding (FCAW)
In flux-cored arc welding (FCAW), a machine is used to continuously feed an electrode into the weld joint. The electrodes are filled with flux to protect the weld from contamination as it melts.[v]
FCAW welding is used in these sorts of applications:
- Pipeline Welding
- General repairs
- Underwater welding
Professionals love flux-cored arc welding for several reasons:
- It’s a quicker process than SMAW.
- FCAW is versatile. It can be an automatic or semi-automatic process.
- FCAW is a mobile process because you don’t need to carry around a tank of shielding gas.
Plasma Arc Welding (PAW)
Plasma arc welding is like tungsten arc welding:
- In both processes, the arc is formed between the work and a non-consumable tungsten electrode.
- Shielding gas is also employed during both processes to protect the weld.
- PAW also uses a plasma gas, which is separated from the shielding gas by placing the electrode in the body of the torch.
The PAW process is commonly used in the following areas:
- High speed sheet welding
- Microplasma welding
- Keyhole welding[vi]
- Medical equipment
- Welding coated steels
Why is Plasma Arc welding popular?
- High welding speeds and deep penetration
- Minimal electrode contamination
- Reliable arc starts
- Wide range of operating modes
- Good for small precision welding applications
- Requires less operator skill
Gas Tungsten Arc Welding (GTAW)
Inert gasses are used to shield the weld, while a foot pedal is used to control the heat. This produces a clean, precise weld.[vii] It’s no surprise that NASA chose this type of welding for the Apollo space program.
Today GTAW/TIG is used in several applications:
- Aerospace industry
- Automotive construction and repair
- Ship fitting
What are the advantages of GTAW/TIG welding?
- It’s used for numerous metals: steel, bronze, nickel, brass, copper, magnesium, aluminum and gold.
- It produces welds without sparks, smoke, or fumes.
- It’s good for detailed designs or curves.
- It can be used on thin and thick metals.
- It’s good for applications that require an attractive appearance.
Submerged Arc Welding (SAW)
Submerged arc welding (SAW) uses a consumable electrode wire fed through a gun into the weld pool, which serves as both the arc and the filler metal. The atmospheric protection in SAW comes from a flux powder that is placed on the surface of the work piece.
The resulting slag is later removed from the finished product.
Submerged arc welding is preferred in a variety of applications:
- Machine components for heavy industry
- Vessels and tanks for pressure and storage use
- Wind tower production
Why do professional welders choose SAW?
- SAW is 4 to 10 times faster than SMAW.
- It can be semi- or fully automatic.
- SAW has high thermal efficiency: 60% compared to 25% for SMAW.
- SAW is a spatter-free process.[viii]
Types of Welding Joints
While there are key differences between SMAW, GMAW and TIG, each of these types of welding uses five common joints to fuse metals. [ix]
- Butt joint: Two metals are joined at the edges on the same plane to create a flush surface.
- Corner joint: Two metals are fused to create a right angle, or a corner.
- Lap joint: One metal overlaps the other, creating a lap joint.
- Tee-joint: Two metals are fused at approximate right angles to each other to form the letter T.
- Edge joint: An edge joint is formed when two metals are fused at the edges to join two parallel or nearly parallel metals.
Welding: A Diversity of Career Options
A career in the world of welding can take you anywhere you want to go—from high up on skyscrapers to under the ocean. Cars, trains airplanes, sea ships and even space rockets are made possible through the process of welding.
If you want to immerse yourself in the different types of welding and be prepared to enter every industry, our professional welding training program can help you get there.