Abstract: A torque nut or screw that allows the nut to be tightened to a preset maximum torque, but prevents excess tightening. The nut or screw includes inner and outer threaded elements that extend along the same axis. The outer threaded element is tapered with respect to the axis. The fastener includes an inner fastening member (7) having fastening threads (8) and an outer female member (10) that is rotatable by means of a spanner, a pair of pliers, a screw driver, or other tool. The female member is connected to the inner fastening member by a coupling (13) having a sufficient strength to transfer to the inner fastening member a torque of a magnitude for which the fastening device is designed. The outer female member (10) is designed to be released upon tightening of the coupling and rotated relative to the inner fastening member (7), but not until the predetermined torque is exceeded. The coupling between the outer female (10) and the inner fastening member (7) includes a conical screw coupling.
Abstract: The invention relates to a fastening element with a torque-limiting function, comprising on the one hand a fastening member (2, 2') with working threads (4), that is to say threads which are active for the fastening function of the element, and on the other hand a gripping member (3, 3') which is arranged so as to be capable of being turned with the aid of a spanner, wrench, screwdriver or other tool for attaching the fastening element (1, 1') and connected or connectable to the fastening member (2, 2') via a torque-transmitting threaded connection (5, 6/17, 18) with sufficient strength in order to be capable of transmitting to the fastening member torque of the size for which the fastening element is intended, and in which the gripping member is arranged to be unscrewed and turned relative to the fastening member, on attachment of the fastening element, only when the torque exceeds a given predetermined torque.