The disclosure relates to an electric induction machine in which a chamfer region is provided between each respective rotor groove and rotor bar at a position corresponding to a radially outer internal corner region of the rotor groove. Suitably, the chamfer region has a relative magnetic permeability less than that of the rotor frame, and an electrical resistivity higher than that of the rotor bar. Moreover, a minimum diameter of the chamfer region is suitably larger than a manufacturing-tolerances derived maximum clearance between the respective rotor groove and robot bar, if any.