GTAW — What It Is and Why It Matters
GTAW (Gas Tungsten Arc Welding) is the formal AWS designation for TIG welding. The name breaks down as: gas (argon/helium shielding) + tungsten (non-consumable electrode) + arc + welding.
GTAW appears on engineering drawings, welding procedure specifications, code documents, and certification records. When a blueprint specifies "GTAW" as the required process, it means TIG welding performed according to the parameters defined in the associated WPS.
The process can operate in DCEN (DC electrode negative) for steel and stainless, AC for aluminum (the alternating polarity provides an oxide-cleaning action), and DCEP in specialized applications. GTAW is specified whenever maximum weld quality and control are required — it is the standard for root passes in pipe welding, aerospace components, pressure vessels, and food-grade stainless fabrication.
Frequently Asked Questions
What does GTAW stand for?
Gas Tungsten Arc Welding. It is the American Welding Society's formal name for the process commonly called TIG (Tungsten Inert Gas) welding. GTAW is the term used in codes, specifications, and certification documentation.
When is GTAW required instead of other processes?
GTAW is commonly specified for root passes in pipe welding, aerospace components, nuclear fabrication, pressure vessels, and any application where maximum weld purity and X-ray quality are required. Many codes allow GMAW or FCAW for fill and cap passes after a GTAW root.