What is the primary function of an arc welding electrode?

The primary function of an arc welding electrode is to act as a component of the welding circuit through which current is conducted. The electrode serves as a conductor that allows electric current to flow, creating the necessary arc between the electrode and the workpiece to generate heat. This heat melts both the electrode and the base metal to form the weld.

While the electrode does facilitate the transfer of current, as mentioned in one of the other choices, it is more accurate to say that it is a fundamental part of the circuit, highlighting its role in enabling the welding process. The protective sheath mentioned in another choice relates to certain types of electrodes that have coatings that help shield the weld pool from contamination, but that is an additional function rather than the primary role. Lastly, measuring weld quality is a separate aspect of welding assessment and does not pertain to the electrode's primary purpose.