A controlled electrical discharge between the electrode and the workpiece that is formed and sustained by the establishment of a gaseous conductive medium, called an arc plasma.

Written verification that a welder has produced welds meeting a prescribed standard of welder performance.

The capacity of a material to be welded under the fabrication conditions imposed into a specific, suitably designed structure and to perform satisfactorily in the intended service.

Weld metal in excess of the quantity required to fill a joint.

A non-standard term for weld pool.