What distinguishes a pure tungsten electrode from a thoriated tungsten electrode?

A thoriated tungsten electrode is distinguished primarily by its enhanced arc stability compared to a pure tungsten electrode. Thoriated tungsten electrodes are alloyed with a small percentage of thorium, which significantly improves their performance during welding applications. This alloying agent allows thoriated electrodes to maintain a more stable arc and provides better electron emission when heated, especially during the initiation and maintenance of the welding arc.

The improved arc stability is crucial for achieving clean, precise welds, particularly when welding thinner materials or when the welder is working in challenging positions. Thoriated tungsten electrodes also tend to resist sintering, which contributes to their longevity and efficiency in various welding scenarios.

The other characteristics mentioned in other choices do not accurately represent the primary distinctions between the two types of electrodes.