Projection welding (PW) is a variation of resistance welding in which current flow is concentrated at the point of contact with a local geometric extension of one (or both) of the parts being welded. This article discusses the applications of PW generally categorized as either embossed-projection welding or solid-projection welding. Different projection-welding configurations are schematically presented and the common variations of solid-projection welding are described. The article describes equipment used and the process requirement for the PW. The process requirements for projection welding of a range of intermediate-gage low-carbon steels are presented in a table.