Abstract: A method of blow molding a component that is to be assembled from a plurality of pieces to insure that apertures used to secure the pieces together are accurately located and effectively formed. The two pieces to be joined are molded in the same mold cavity and are held in a predetermined longitudinal position relative to each other in the mold cavity and which location corresponds to the assembled location of the pieces. The pieces are simultaneously apertured while the molded plastic is still warm by punches that are affixed to a common actuating member. This insures that the parts will fit well when assembled.