glossary

A test used to identify a metal. The metal is brought into contact with a power driven, high speed grinding wheel which produce spark patterns. These patterns are unique to several classes of ferrous metals.

Metal particles expelled during welding that do not form a part of the weld.

arc welding process / procedure used in the pipe industry.

A resistance welding method commonly used to join thin sheet materials by overlapping joints.

Unlike the plasma gas, the secondary gas (also referred to as secondary gas) does not pass through the orifice of the nozzle. It passes around the nozzle and forms a shield around the arc.