A rotor core of an induction motor fabricating method includes a cylindrically shaped steel laminate stack having a plurality of longitudinal grooves distributed around the periphery of the steel laminate stack. A plurality of conductor bars are each located in one of the plurality of longitudinal grooves and each includes a first end projecting from a first end of the steel laminate stack. A shorting end ring includes a plurality of grooves aligned with and mated to the first ends of the conductor bars. The shorting end ring is affixed to the rotor core assembly by a lock ring assembled when at a thermally expanded condition to the rotor core when at a thermally contracted condition.