Carbon steel, mild steel, stainless, and aluminum all MIG well with the right wire and gas combination. Thicknesses run from light gauge sheet metal up through quarter-inch and thicker structural steel, with multi-pass welds for the heavier sections.
Some materials and thicknesses are better served by stick or flux-core for outdoor work, by TIG for thin precision welds, or by hardfacing for wear surfaces. We’ll tell you which process fits the job.