GMAW — What It Is and Why It Matters
GMAW (Gas Metal Arc Welding) is the official AWS designation for the process commonly known as MIG welding. The name describes exactly what happens: gas (shielding) + metal (consumable wire electrode) + arc + welding.
GMAW encompasses all wire-feed welding using solid wire and external shielding gas, including short-circuit transfer (low heat, good for thin material and out-of-position work), globular transfer (higher heat, limited to flat and horizontal), spray transfer (high-energy, high-deposition for thick material in flat/horizontal), and pulsed spray (an advanced mode that alternates between high and low current peaks for positional welding with spray-quality results).
The GMAW designation appears on welding procedure specifications (WPS), blueprints, code documents, and certification paperwork. Understanding these formal terms is essential for anyone pursuing AWS certifications or working under structural welding codes like AWS D1.1.
Frequently Asked Questions
Is GMAW the same as MIG welding?
Yes. GMAW is the formal AWS designation; MIG is the common shop name. They refer to the same process — wire-feed welding with solid wire and external shielding gas. You will see GMAW on blueprints, codes, and certifications, while MIG is what everyone calls it on the shop floor.
What are the four GMAW transfer modes?
Short-circuit (low heat, positional), globular (higher heat, flat/horizontal only), spray (high-energy, flat/horizontal), and pulsed spray (alternating current peaks allowing spray-quality welds in all positions). Each mode suits different material thicknesses and welding positions.