A method and apparatus for producing the ring member of a gerotor gear set. Ring members are first formed roughly to size by broaching a stack of blanks. The honing of the crests and flanks of the teeth is done with a honing mandrel having tapered cross section with the same shape as the star member of a gerotor gear set. The honing mandrel is reciprocated and at the same time is given rotational and orbital movements which correspond to the movements of the same character which occur in the operation of a gerotor gear set wherein the star member may have both rotational and orbital movement relative to the ring member of the gear set.