Resistance spot welding has been used in industrial production since around 1930 in order to join together sheets made of different combinations of metals. Applications are mainly in the automotive industry in bodywork and vehicle construction, but are also found in other areas of sheet metal processing. The electrical industry uses resistance spot welding to produce contact sets for relays, connections of coils or capacitors. With certain restrictions, it is also possible to join materials that are otherwise not well suited to welding.