In electric arc welding, the welding joint is produced by heating with electrical spark. Itis only a electrical spark between electrode (wire/stick is used as filler metal to welding zone) tip and work piece(i.e the metal to be welded), otherwise it is nothing. It is also called fusion welding process. It is work in a closed electrical circuit in which current flows. If a small gap formed in the circuit then there an electrical spark is occurred, which is called electrical arc. In this spark or arc are contain a huge amount of temperature like 34000C-40000C. Due to this huge temperature, the weld metal can be fuse in arc welding process.