What type of tungsten is commonly used for welding applications?

In welding applications, both pure tungsten and thoriated tungsten are widely used due to their individual characteristics that enhance the Welding process. Pure tungsten is favored for its good arc stability and is often used for specific applications like AC welding on aluminum, where it performs exceptionally well. Thoriated tungsten, on the other hand, contains a small percentage of thorium oxide, which allows for a lower work function and improves the electrode's performance. This type is preferred for DC welding, especially on ferrous materials, as it provides better durability and electrode life.

The versatility in choosing these types of tungsten electrodes means that welders can select the appropriate material based on the specifics of the job, such as the type of metal being welded and the welding conditions. This is why the option stating that both pure and thoriated tungsten are commonly used is considered correct. It highlights the importance of understanding how different tungsten materials affect the welding process and the application at hand.