Methods of machining a single piece hub with integral upper and lower female cones includes providing a single piece hub with upper and lower conical voids having respective narrow ends proximal each other and respective wide ends distal each other. Surfaces of the voids are machined using a tool provided from a single side of the hub that is dimensioned to fit through an opening defined by the interface between the narrow ends of the conical void. The tool can be moved parallel to a rotational axis for accessing conical surfaces of both voids and perpendicular to the rotational axis while contacting the surfaces so as to produce a final machined surface.