What is the primary purpose of the coating on an electrode?

The primary purpose of the coating on an electrode is to prevent impurities from entering the weld. The coating acts as a shielding agent that protects the molten weld pool from atmospheric contamination, which can lead to defects and weaken the weld. This is particularly crucial because contaminants such as oxygen and nitrogen can create gas porosity and other issues in the weld joint.

In addition to protective functions, the coating also contributes to the stability of the arc and can help produce a better-quality bead. However, its primary role remains focused on creating a clean and uncontaminated environment for the welding process, which is essential for ensuring strong and reliable welds.