The ESAB Mig-Mag Wires stands for Metal Inert Gas and MAG stands for Metal Active Gas. As you can see the difference between these 2 is the type of shielding gas thats being used during welding. Often the shielding gas comes from a cylinder but you can also choose welding wires filled with gas. Metal inert gas (MIG) and metal active gas (MAG) welding is a semi-automatic process in which a metal arc burns between a current carrying wire electrode and the workpiece, protected by a shielding gas. ESAB Mig-Mag Wires are very effective and useful.