A drive design for a fastening element in-stalled using screws, in particular, a screw or a nut, comprises drive surfaces (13) disposed at least approximately in radial planes and transition surfaces (15) disposed between said drive surfaces. In one embodiment of the outside of the surfaces, the surfaces form a saw shape, In this way, when rotation is in one direction in which a tool en-gages with the drive surfaces (13), torque-application results, whereas in the opposite rotational direction a force component is produced that acts on the tool without engaging with the screw drive design. A tool is designed to be complementary to the screw drive design. The screw drive design can be an inner shaping as well an outer shaping. The same applies for a nut. This drive design is intended for designing a screw connector in such a way that it can be tightened once, but cannot be loosened any longer.