Abstract: An electric motor housing and heat sink, and the method of assembling the same, in which a housing, constructed of electrically insulating material subject to thermal distortion, includes integral means for orienting and securing a metal heat sink therein, the latter having passages through which cooling air is drawn. The orienting means comprises deformable or meltable means such as pins integral with the housing and adapted to extend through apertures in the heat sink. In addition, a shaft bearing may either be preassembled in the heat sink before assembly to the housing, or the heat sink bored and the bearing inserted therein after the heat sink is assembled to the housing.