Drive element which has an inner driving profile which defines a profile axis (P I) and has on its inner side a plurality of concave, i.e. curved inwardly towards the profile axis (P I), drive surfaces arranged uniformly distributed around the profile axis (P I) between which planar or convexly curved transition surfaces are provided, or which has an outer driving profile which defines a profile axis (P A) and has on its outside a plurality of concave, i.e. curved inwardly towards the profile axis (P I), drive surfaces arranged distributed uniformly about the profile axis (P A) between which planar or convexly curved transition surfaces are provided, wherein in cross-section, the transition points or transitions between the drive surfaces (5, 10) and the transition surfaces (7, 7a) lie on a common inner circle with the inner diameter Di, and the drive surfaces lie on outer circles of diameter Da distributed uniformly around the profile axis (P I, P A) and are formed symmetrically with respect to their longitudinal central plane enclosing the profile axis (P I, P A), characterized in that the outer diameter Da and the center-to-center distance L between the centers of the outer circles and of the inner circle are selected as a function of the inner diameter D i such that the normal force acting at the transition points between in each case one drive surface (6, 10) and the adjacent transition surface (7, 7a) when a torque M D about the profile axis (P I, P A) is introduced into the drive profile (5, 9), is tangential to the drive surface (6, 10) adjacent to the one drive surface (6, 10) or runs within the latter, i.e. is directed into the central region of the driving profile (5, 9) which is positioned between the drive surface (6, 10) and the profile axis (P I, P A). which has an inner driving profile which defines a profile axis (P I) and has on its inner side a plurality of concave, i.e. curved inwardly towards the profile axis (P I), drive surfaces arranged uniformly distributed around the profile axis (P I) between which planar or convexly curved transition surfaces are provided, or which has an outer driving profile which defines a profile axis (P A) and has on its outside a plurality of concave, i.e. curved inwardly towards the profile axis (P I), drive surfaces arranged distributed uniformly about the profile axis (P A) between which planar or convexly curved transition surfaces are provided, wherein in cross-section, the transition points or transitions between the drive surfaces (5, 10) and the transition surfaces (7, 7a) lie on a common inner circle with the inner diameter Di, and the drive surfaces lie on outer circles of diameter Da distributed uniformly around the profile axis (P I, P A) and are formed symmetrically with respect to their longitudinal central plane enclosing the profile axis (P I, P A), characterized in that the outer diameter Da and the center-to-center distance L between the centers of the outer circles and of the inner circle are selected as a function of the inner diameter D i such that the normal force acting at the transition points between in each case one drive surface (6, 10) and the adjacent transition surface (7, 7a) when a torque M D about the profile axis (P I, P A) is introduced into the drive profile (5, 9), is tangential to the drive surface (6, 10) adjacent to the one drive surface (6, 10) or runs within the latter, i.e. is directed into the central region of the driving profile (5, 9) which is positioned between the drive surface (6, 10) and the profile axis (P I, P A).