Abstract This presentation reviews selected innovations related to induction hardening of various automotive powertrain transmission and engine components, including but not limited to induction surface hardening of complex geometry shafts. Thanks to several innovative designs (patented and patent pending), important goals were achieved. Process flexibility in shaft scan hardening has been substantially enhanced thanks to a novel inverter design that allows controlling independently frequency and power during scanning. This innovation allows improving quality of induction hardened components maximizing production rate and process flexibility. When applying single-shot hardening for heat treatment of output shafts, flanged shafts, yoke shafts, sun shafts, intermediate shafts, drive shafts and others, coil life is often limited due to a necessity to “squeeze” coil current in a certain area, maximizing power density. This seemingly unavoidable feature of the great majority of single-shot inductors represents a “weak link”, limiting coil life expectancy. Thanks to innovative design (patent-pending) of a single-shot inductor, its life was increased approximately nine times. Process sensitivity has been dramatically reduced. Other benefits include measurable improvement in process robustness, coil reliability and maintainability.