A driver is designed for coaxial and non-coaxial driving of a fastener with a lobed drive recess. The driver has a part spherical drive head connected by a neck to the drive end of a shank coaxially therewith, the outer surface of the head defining circumferentially alternating lobes and valleys extending longitudinally in planes containing the driver axis. The head is shaped such that its longitudinal cross section in one of the planes through a valley defines a central part-spherical portion and frustoconical end portions substantially tangent to the central portion respectively at its opposite ends. The head is further shaped so that, in its transverse cross section, each of the lobes has a leading flank and a trailing flank shaped and dimensioned that the flanks do not define undercuts which would make molding of the driver difficult.