In GTAW history, which shielding gas was originally used?

• A. Argon
• B. Neon
• C. Helium
• D. Hydrogen

Answer: (C)

Shielding gas in GTAW protects the molten weld and also shapes the arc. Helium was the first shielding gas used in GTAW history. Its properties produce a hotter, more energetic arc, which was advantageous for getting good fusion in the early TIG processes and for welding tougher or thicker sections. That early advantage made helium a natural starting choice despite its higher cost and more specialized handling. Later, argon became the standard because it offers a stable arc and is much more economical, while still providing excellent shielding for many metals. Neon and hydrogen have limited or specialized roles and aren’t the typical choices for the original GTAW shielding gas.