Abstract: A connecting element in the form of a screw or bolt, nut or washer for a screw connection has at its bearing surface at least one projection and at least one radially further outwardly disposed surface region. The height and cross-section of the projection are so dimensioned that on tightening of the screw connection the projection is elastically or plastically deformed to such an extent that on reaching a predetermined prestress force the radially outwardly disposed area region comes into engagement. When the screw connection, usual in practice, is tightened up to a predetermined tightening torque, the invention reduces the tolerance range of the prestress force corresponding to the tightening torque. The change in the torque vs. rotational angle differential quotient which occurs when the projection has been sufficiently deformed for the radially outwardly disposed area region to come into engagement may also be employed as criterion for terminating the tightening operation.