Abstract: A cylindrical commutator is provided with a plurality of segments arranged at equal intervals around an axis, each of which is provided with a groove on an inner surface thereof and one or more anchors extending from edges of the groove. The grooves and the anchors are extended over substantially the total length of the segments and respectively have end steps and end edges at ends near the hooks, or the anchors can be formed in pair and the pair of anchors are connected with each other at the ends near the hooks.

Abstract: A cylindrical commutator is manufactured as follows. On the internal peripheral surface of a cylinder of base material having a plurality of hooks at one end, cuts are formed in a circumferential direction corresponding to the respective hooks, and projections are formed toward the inside by cutting. The base material is set to a molding die, and the prepared projections are embedded into the mold resin. Slits are processed at equal intervals in a circumferential direction on the external peripheral surface of the mold resin, and the hook and the prepared projection are divided for each segment. The segments are firmly integrated together with the mold resin.