MIG welding (Metal Inert Gas) joins metals by continuously feeding a consumable filler wire through an electric arc, which melts and fuses the base materials together. The filler metal is deposited precisely where the electrode contacts the workpiece, forming a strong, consistent seam. Shielding gases—typically inert or semi-inert—protect the weld area, controlling the arc and heat to ensure quality and reduce contamination. MIG welding is ideal for thicker materials requiring heavy, durable seams but carries a higher risk of burn-through on thinner metals compared to TIG welding.