The Plasma Arc Cutting (PAC) process severs metals by using a constricted arc to melt a localized area of a work piece, removing the molten material with a high velocity jet of ionized gas issuing from the constricted orifice. The ionized gas is a plasma, hence the name of the process. Plasma arc operate typically at temperatures 10000-14000 Celsius degrees. Plasma cutting was unvented in the mid 1950’s and became commercially successful shortly after its introduction to industry. The ability of the process to sever any electrically conductive material made it especially attractive for cutting nonferrous metals that could not be cut by the oxyfuel cutting (OFC) process. It was initially used for cutting stainless steel and aluminum. As the plasma cutting process was developed, it was found that it had advantages over other cutting processes for cutting carbon steel as well as nonferrous metals.