An electrode (covered with flux) creates an arc at 3000-6000°C. The electrode core melts to form the weld metal; the flux coating decomposes to produce shielding gas and slag that protects the molten pool. Equipment is simple: welding power source + electrode holder + cables. Suitable for outdoor work, steel structures, and repair.
E4303 (J422): General purpose, low carbon steel. E5016/E5015 (J506/J507): Low hydrogen type, medium carbon steel, critical structures. Stainless steel electrodes (A102/A132): For stainless. Cast iron electrodes (Z308): For repair.
Rule: match strength or match composition.
Typical deposition rate: 1-3 kg/hour vs 5-10 kg/hour for CO₂ welding. This is why SMAW is being replaced for production work but remains essential for field welding, tight spaces, and repairs.