Induction heat treatment is a common method for hardening and tempering of crankshafts, which are necessary components in almost every internal combustion engine for cars, trucks, and machinery, as well as pumps, compressors, and other devices. Similar to crankshafts, camshafts also belong to the same group of the critical engine/powertrain components. This article focuses on induction technologies used for surface hardening and tempering of automotive crankshafts, and provides general information on U-shaped inductors with crankshaft rotation and clamshell or split inductors without crankshaft rotation and their pros and cons. It also describes the effect of post-heat-treatment processes in crankshafts. The article concludes with a discussion on induction hardening of camshafts that focuses on those used in automobiles and truck engines.