Introduction To TIG Welding

Key Points

- Tungsten inert gas (TIG) welding, also known as gas tungsten arc welding (GTAW), is a type of welding that uses a non-consumable tungsten electrode and an inert shielding gas.

- TIG welding allows for the joining of objects without the use of filler material, resulting in neater and spatter-free welds.

- TIG welding requires precision and control, with the welder using a foot pedal or other device to control  electrical current to the weld puddle.

- There are different methods for setting up a TIG welding torch, including scratch starts, lift starts and high-frequency starts.

- TIG welding is used in various industries, including race car fabrication, ship fitting, aerospace manufacturing and motor vehicle repair. It produces stronger welds and offers versatility but has a greater learning curve and higher cost compared with other welding processes.

Tungsten inert gas (TIG) welding, also known as gas tungsten arc welding (GTAW), is a type of welding responsible for securing some of the world’s most important equipment and machinery.

During the TIG welding process, a non-consumable tungsten electrode is used. The weld puddle and tungsten are cooled and protected with an inert shielding gas (like helium or argon), just like with gas metal arc welding (GMAW), also known as MIG welding.

While MIG welding uses a continuously fed wire that also acts as filler material, the tungsten electrode heats the objects enough so they can form a bond. TIG welding enables the joining of objects without the use of filler, though a filler metal is commonly used in TIG welding. TIG welding can be used for direct metal-to-metal welds and results in neater, spatter-free welds that are generally free of defects.

Interested in finding out more about this form of welding? We answer a lot of questions, so keep on reading!

How TIG Welding Works

Now that you know the basics of what TIG welding is, here are more details on the process and specifics about how it works.

TIG welding process

During the TIG welding process, an arc is formed between the tungsten electrode and the work. The arc that is produced by the electrode is intense and makes TIG welding perfect for high-quality welds. The electrode is not consumed during the weld.

TIG welding requires great precision. It’s similar to welding with an oxy-acetylene torch, in that the welder holds the torch in one hand and feeds a filler rod into the weld pool with the other hand. The difference with TIG, however, is that the welder is also controlling the electrical current to the weld puddle with a foot pedal or other device on the torch at the same time.

TIG welding setup / torch setup

There are a few different methods that can be used for a TIG welding setup. There are scratch starts, lift starts and high frequency starts.

Scratch starts rely on the welder to scratch the tip of the tungsten on a workpiece (like striking a match). In scratch starts, the weld can get contaminated with particles from the tungsten.

In a lift arc technique, a welder uses a foot pedal, but there is no arc jumping between the tungsten and the metal. A cup is put down on the metal, which allows the welder to roll a torch upright and lifted in a slight maneuver. Lift starts result in a low-voltage output.

High-frequency starts are the most common way to set up a TIG welding torch. Eliminating the need to strike an arc, the high-frequency start feature creates an arc by generating high voltage, with pressure needed to jump between the torch and metal.

Read: How To Become a Welder

Electrodes used in TIG welding

As its name implies, the electrodes used in TIG welding are tungsten electrodes. Tungsten creates a non-consumable electrode — it has a high melting point and offers great amounts of electrical conductivity.

Tungsten electrodes can be alloyed with a range of metals depending on the type of weld they are going to be used for. With tungsten electrodes, the arc and weld pool are protected from contamination by inert gas.

TIG welding temperature

The TIG welding process operates at temperatures over 6,000 degrees Fahrenheit!

What Is TIG Welding Used For?

GTAW first emerged in the early 1940s, when Russell Meredith created the process using a tungsten electrode arc and helium for the shielding gas. Today, TIG welding has many applications, including:

• Race car fabrication and motorsports applications
• Ship fitting
• Bicycle manufacturing and repair
• Aerospace and space vehicle manufacturing
• Piping, repair tools and dies
• Motor vehicle repair and construction
• Diverse industries including pharmaceutical, nuclear and art

If the materials that are being welded are very thick, like thick pieces of sheet metal, TIG welding is generally not as effective as MIG welding. But if the materials are electrically resistant and heat up quickly, TIG welding may be appropriate. TIG welding is also useful when a weld does not require filler metal, like in cases where thin materials are combined.

Read: The Different Welding Processes

Advantages of TIG welding

There are many advantages to TIG welding, including:

• Stronger welds: TIG welding produces stronger results because it has high corrosion resistance and penetrates deeper.
• Versatile: TIG welding can be done with or without filler metals, and other variables like heat input can be controlled.
• Clean: TIG welding does not produce spatter, eliminating the need for cleanup later.

Disadvantages of TIG welding

Along with the advantages of TIG welding, there are also some disadvantages to keep in mind:

• Learning curve: TIG welding is considered one of the most difficult welding processes to learn and master, requiring a lot of skill.
• Low deposition rate: The process of TIG welding has a lower deposition rate than other welding processes, causing projects to take longer. Deposition rate refers to the amount of filler metal melted into the weld joint.
• Higher cost: Since deposition rates are lower and the process can’t be automated, the cost of TIG welding can increase faster than other processes.

TIG Welding FAQs

What does TIG stand for in welding?

TIG stands for “tungsten inert gas.”

What does GTAW stand for in welding?

GTAW stands for “gas tungsten arc welding.”

Is GTAW the same as TIG welding?

GTAW and TIG welding are the same and are terms that are often used interchangeably.

What gas is used for TIG welding?

Inert shielding gases are used in TIG welding, just like in MIG welding. Inert gases do not undergo chemical reactions. Common types include argon and helium.

What’s the difference between GMAW and GTAW?

While GMAW and GTAW are similar in the fact that they are protected by inert shielding gases, they do differ. MIG welding uses a continuously fed wire as a filler material, and in TIG welding a tungsten electrode is used that delivers current to an arc.

TIG Welding Classes

Students in the Welding Technology program at Universal Technical Institute (UTI) learn GTAW fundamentals and applications. In the Gas Tungsten Arc Welding course, students learn:

• Characteristics and safety considerations of GTAW welding
• Direct and alternating current methods in GTAW welding
• How to make gas tungsten arc welds on different metals

The lab work UTI offers enables students to practice GTAW welding and other welding processes in a safe and supportive environment. Edward Lopez, Welding Technical Team Leader at UTI Rancho Cucamonga, says, “Once students are out in the lab, and they start to piece together the theory portion and the hands-on portion, you see an instant understanding.”

Attend a UTI Welding Campus

The opportunity for hands-on education and training to prepare for a career in welding is available at UTI campuses nationwide.¹ You can learn more about these specific locations by clicking the links below:

• Avondale, Arizona
• Long Beach, California
• Sacramento, California
• Rancho Cucamonga, California
• Miramar, Florida
• Lisle, Illinois
• Bloomfield, New Jersey
• Mooresville, North Carolina
• Exton, Pennsylvania
• Austin, Texas
• Dallas/Fort Worth, Texas
• Houston, Texas

Our welding program is designed to help students gain the skills and knowledge they need for an entry-level position in the industry. During the 36 weeks of training, students are also taught other widely used arc welding processes.

Interested in pursuing a welding career in a growing industry? Request more information today!