Resistance soldering (RS) can be applied to electrically conductive materials that allow the passage of electric current. The process can be used for selective spot soldering of small components, for the soldering of closely placed parts on an assembly, or for heat restriction when necessary. This article explains that the RS process can be used in all soldering operations and with all solderable metals. It provides information on the applications, preassembly practices, the equipment used and the training required for soldering personnel.