Gas metal arc welding is one of the most versatile and efficient joining processes. With the proper selection of equipment, electrical characteristics, and shielding gas, it can be used on a wide variety of materials and material thicknesses, applied to work requiring out-of-position welding, and used for special applications such as spot welding. Because it employs a continuously fed solid or alloy-cored electrode at high current densities, it will deposit welds at a significantly higher rate than the shielded metal arc welding process and will generally exhibit a high percentage of arc-on time. Little post-weld cleanup is required. The process can be easily and economically automated and has become the process of choice for robotic installations.
However, the process is more complicated than the manual processes, such as shielded metal arc welding or gas tungsten arc welding, and the equipment is more expensive. Gas metal arc welding requires that those involved in its application have a good understanding of the various equipment and consumable material components and their functions, and how selection of the various parameters affects arc characteristics and usability. After the initial setup, the ability of the welder or welding operator recognize when the process is performing correctly and what to do it is not will be the keys to a successful application.