What is the Electrode for MMA welding

The coated electrode is composed of two parts or a metal core that acts as a filler material and a coating that provides protection.
During welding, the electrode core melts and, in the form of drops, is transferred to the melt pool; at the same time, the coating also follows the core in the melt pool in such a way as to form a cup at the end of the electrode; with this conformation, the coating contributes to the protection of the end of the electrode where the material is melted and also creates a local overpressure of the gases inside, capable of causing the detachment and transfer of the drop.