Metal-cored welding wire provides filler metal for GMAW (gas metal arc welding) tasks. This tubular wire has a powdered metal core and typically provides faster travel speeds and higher deposition rates than solid MIG wire. It requires external shielding gas to keep contaminants out of the weld pool. Also known as welding wire or filler wire, this wire typically comes on a coil or spool and is fed through a compatible welding gun. An arc is created between the wire and a workpiece, and the heat from the arc melts and fuses material from the workpiece and the wire to create a weld.