What type of tungsten electrode is most commonly used in GTAW?

The most commonly used tungsten electrode in Gas Tungsten Arc Welding (GTAW) is tungsten with small amounts of thorium. This type of electrode is known for its excellent performance characteristics, which include higher current-carrying capacity and improved arc stability compared to pure tungsten electrodes. The addition of thorium enhances the ability of the electrode to maintain a clean, steady arc, making it particularly effective for welding a variety of materials, especially those that require precise control and clean welds, such as aluminum and stainless steel.

Thorium-oxide tungsten electrodes (typically identified by the red color band) are favorable for their ability to increase the life of the electrode and provide better ignition properties. This results in less downtime for electrode changing during welding operations, which is crucial in both industrial and experimental settings.

In contrast, while pure tungsten does have its applications, it does not perform as well under high heat and demanding conditions. Alloyed tungsten and plastic-covered tungsten are not commonly used in GTAW for general welding applications, as plastic coverings are not compatible with the high temperatures involved, and alloyed tungsten options do not offer the same benefits as thorium-enhanced electrodes for the majority of welding scenarios.