Abstract: A two phase stepper motor having a rotor shaft with a multi-pole rotor and a stator assembly in magnetic flux relationship with the rotor. The stator assembly includes a plurality of sequentially stacked laminations which are each provided with eight stator poles with each immediately successive stator pole having an opposite phase and each being at a 45.degree. index spacing from the immediately adjacent lamination. The stepper motor also contains a multi-phase winding for energizing the stator poles to operate the rotor in successive discrete steps. The stepper motor housing includes first and second end pieces having a pair of triangular cross-section members forming notches therebetween on a first pair of oppositely disposed corners which receive and retain an abutment post on a second pair of oppositely disposed corners from the opposite end piece thereby interlocking the first and second end pieces relative to one another.