Which property is characteristic of tungsten as an electrode material in GTAW?

• A. High melting temperature
• B. Low melting temperature
• C. Low tensile strength
• D. Rapid oxidation in air

Answer: (A)

The key property here is a very high melting temperature. In GTAW, the electrode must act as a nonconsumable guide for the arc, lasting in the intense heat without melting away. Tungsten’s melting point is around 3422°C, vastly higher than most welding temperatures, so it remains solid and maintains the arc shape during welding. This stability is essential for precise control and long electrode life in TIG welding.

Shielding gas (like argon or helium) protects the tungsten from oxidation, so rapid oxidation in air isn’t a characteristic of properly shielded GTAW; the process is designed to prevent exposure to air. That’s why the other properties listed aren’t defining factors: a low melting temperature would cause the electrode to melt away quickly, and tensile strength or rapid oxidation in air aren’t the determining traits for why tungsten is chosen as the GTAW electrode.