What is TIG welding?

Key takeaways

• TIG welding uses a non-consumable tungsten electrode and shielding gas to produce precise, high-quality welds.
• The process allows exceptional control over heat input, filler material, and weld appearance.
• TIG welding is widely used in industries requiring clean, consistent welds, including semiconductor manufacturing, medical device fabrication, and specialty gas delivery systems.
• The process is well suited for welding stainless steel tubing, thin materials, and high-purity fluid system components.
• Proper shielding gas, weld preparation, and operator expertise are essential for achieving consistent TIG welding results.

It goes by different names: gas tungsten arc welding (GTAW) and tungsten inert gas welding (TIG), but what is TIG welding?

TIG welding is widely used in industries where weld quality, cleanliness, and precision directly affect system performance. Because the process uses a non-consumable tungsten electrode and allows tight control of heat input and filler material, TIG welding is particularly well suited for applications involving stainless steel tubing, thin-wall assemblies, and high-purity fluid systems.

In sectors such as semiconductor manufacturing, medical devices, and specialty gas delivery systems, weld integrity is not just a matter of strength. It is also about preventing contamination, ensuring leak-tight performance, and maintaining consistent internal surface quality. These requirements are why TIG welding continues to be a trusted process in environments where precision fabrication matters most.

“Manipulating lightning is the best analogy for what TIG welding encompasses,” says Brian Thessen, a journeyman welder with more than 30 years of experience.

TIG welding is a manual operation where two ferrous or non-ferrous materials join together using heat from an arc generated by a non-consumable tungsten electrode. Tungsten is ideal due to its high melting point of 3,410 degrees Celsius.

Axenics’ technicians perform TIG welding on metals. To keep the metal from oxidation, inert gas such as 99.9% pure argon shields the environment.  

The manual process includes a welder utilizing a torch to manually execute the welds. This is not beginners’ welding, as TIG creates some of the most-intricate, refined welds humanly possible.

“TIG welding is probably the toughest welding skill to perfect as it requires refined dexterity,” Thessen said. “You rely on both hands and both feet. You stand on one foot while using a pedal remote with the other one. You control a welding torch with one hand, and the other hand holds the filler metal that helps create a super-clean precision weldment.”

When it comes to TIG welding, inexperienced welders can run into problems.

TIG challenges

• Sugaring (oxidation): When the root side of a weld is not protected from oxygen, sugaring or oxidation can occur. The result looks like the granules of sugar, and this area of the weld is weak and at risk for cracking, corrosion and other faults.
• Using the wrong arc length: A short arc length (not enough voltage) can cause the tungsten electrode to melt too slowly, which can result in an incomplete weld fusion and other issues. Long arcs (too much voltage) often result in weld porosity, excessive spatter of the filler metal into the weld joint, undercuts and other challenges.
• Using dirty filler material: Filler metals that contain particles or other contaminants will not produce a clean weld, and even can cause a weld to fail. Using dirty filler material goes against the basic principle of clean welding
• Creating craters: Weld craters can happen when a weld pool does not contain the adequate volume after cooling to overcome shrinkage stress, which can cause cracks in the weldment. Slowly reducing the current when completing the weld is one way to avoid this issue.  
• Creating warped or defective welds due to unbalanced heating: A frequent cause of excess heating on the tungsten is electrode positive duration, making it difficult to control the weld puddle. 

Do your due diligence when researching TIG welding services to ensure you work with experienced welders.

“A lot of us can run, but most of us won’t win a marathon. TIG welding is that gold medal standard,” Thessen said.

TIG welding is the preferred process for welding critical joints and fusing large tubes and pipes that generally don’t fit into an orbital welding machine and for open root passes. Joining root passes is the most important part of a weld, so integrity and cleanliness is critical there.

TIG welding is also handy when a project requires butt welds. The filler material used in TIG welds makes butt welds and fillet welds on tee, corner and lap joints. A skilled welder completes butt welds and fillet welds with zero splatter from the filler metal.

TIG welding for metal joining

TIG welding offers two metal joining processes, autogenous weldments and homogenous weldments. Autogenous weldments don’t require filler materials, and homogenous weldments do use filler materials. TIG welding is also known for its versatility as TIG helps fuse metals including stainless steel (Axenics uses 300 series stainless), copper, Inconel alloy, titanium and aluminum.

TIG welding for multiple industries

That versatility lends itself to use in a variety of industries where that require very small, very pure welding jobs, such as those in the semiconductor, chemical processing, medical device and alternative energy industries.

“TIG welding results in intricate weldments on components for life-saving devices,” Thessen added.

He also teaches welding at the college level, using the acronym CLAMS to introduce the fundamentals of TIG welding. What does C.L.A.M.S. stand for in welding?

• C = Current arc
• L = Length
• A = Amperage
• M = Manipulation
• S = Speed

Axenics does not consider TIG weldments complete until they’re leak tested to ensure their integrity, and our welders are certified by the American Society of Mechanical Engineers. The TIG welding process takes time to perfect, but the results are the cleanest, purest welds available. 

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