Resistance[edit]
Main article: Resistance welding
Resistance welding involves the generation of heat by passing current through the resistance caused by the contact between two or more metal surfaces. Small pools of molten metal are formed at the weld area as high current (1000–100,000 A) is passed through the metal.[36] In general, resistance welding methods are efficient and cause little pollution, but their applications are somewhat limited and the equipment cost can be high