Which properties of tungsten make it well-suited for GTAW?

• A. Hardness
• B. Tensile Strength
• C. Ductility
• D. High melting temperature and good electrical conductivity

Answer: (D)

Tungsten’s suitability for GTAW hinges on keeping the electrode solid while carrying the welding current. The arc in GTAW is extremely hot, so an electrode material must have a very high melting point to avoid melting away. Tungsten’s melting point is among the highest of all metals, so it remains intact throughout the welding arc. At the same time, it needs to conduct enough electricity to sustain a stable arc, and tungsten provides good electrical conductivity for this purpose. Together, these properties let the electrode stay non-consumable, maintain arc stability, and minimize contamination of the weld.

Other properties like hardness, tensile strength, or ductility aren’t the primary drivers for the electrode in GTAW. Those traits don’t determine the electrode’s ability to withstand the arc or transfer current as effectively as a high melting point and good electrical conductivity do.