Which of the following part(s) of the torch must also be changed when a different size tungsten electrode is used?

When using a different size tungsten electrode in TIG welding, it is essential to change the collet and the collet body because these components are specifically designed to grip the tungsten electrode securely and maintain proper electrode alignment. The collet is the part that holds the electrode in place, and it is contoured to match the diameter of the tungsten. If a larger or smaller diameter tungsten is used, a collet that properly fits that size must be selected to ensure a secure grip and stable arc.

The collet body, on the other hand, serves to hold the collet in position within the torch. When changing the size of the tungsten electrode, the collet body may also require adjustment or replacement to accommodate the different collet size and ensure a proper fit within the torch assembly. This combination is crucial for maintaining optimal welding performance and preventing issues such as poor arc stability or improper alignment of the electrode.

While other parts of the torch may influence performance, they do not specifically need to be changed solely because of a change in electrode size. This is why emphasizing the necessity of changing both the collet and the collet body is important in maintaining effective welding practices.