What characteristic of thoriated tungsten makes it effective for welding?

Thoriated tungsten electrodes are particularly effective for welding due to their ability to provide better arc stability. This characteristic results from the addition of thorium oxide to the tungsten. When heated, thoriated tungsten produces a clean, stable arc, which is essential for high-quality welds, especially in applications such as GTAW (Gas Tungsten Arc Welding). The improved arc stability allows for more precise control of the welding puddle, leading to uniform weld bead formation and minimizing the risk of defects during the welding process.

While other characteristics, such as a higher melting point and lower heat conductivity, may contribute somewhat to the performance of tungsten electrodes, it is the enhanced stability of the arc that significantly impacts the welding process. Additionally, color coding helps in identifying the type of electrode and can assist welders in choosing the correct one for a task, but it does not influence welding performance itself.