MIG (Metal Inert Gas) and TIG (Tungsten Inert Gas) welding represent different approaches to gas-shielded arc welding, each offering distinct advantages for specific applications. Understanding when to apply each process optimizes weld quality, productivity, and cost in fabrication operations.

MIG welding (GMAW – Gas Metal Arc Welding) uses consumable wire electrode fed continuously through the welding gun, with shielding gas protecting the weld pool. This process offers high deposition rates, good productivity, easier operator training, and suitability for thicker materials. MIG excels for production welding on carbon steel and stainless steel.

TIG welding (GTAW – Gas Tungsten Arc Welding) uses non-consumable tungsten electrode with separate filler metal addition, producing precise, high-quality welds. TIG provides superior weld appearance, excellent control for thin materials, capability for exotic materials, and low spatter. The process suits critical welds, root passes, and materials requiring clean, defect-free welds.

Selection depends on material, thickness, quality requirements, and economics. For ASME pressure vessel fabrication, TIG often produces root passes for quality, while MIG fills and caps for productivity. Thin stainless steel favors TIG; thick carbon steel favors MIG. Exotic alloys like Inconel typically require TIG control.