A chip-removing tool of a surgical torque-transferring instrument includes a distal engagement segment or tool head which is adjoined by a tool shaft whose proximal end portion is prepared for a torque-transferring insertion into a tool mounting of the instrument. The proximal end portion is subdivided at least in a functional section for torque transmission and a functional section for axial locking which is axially spaced therefrom. The functional section for axial locking, with respect to its geometry, includes parameters which are intended to be changed and cooperate according to the key/keyhole principle only with one tool mounting including corresponding geometrical mating parameters for a correct mounting of the tool.