Abstract: A quick-clamping nut for a fastener assembly with mutually cooperating threaded bolts and nuts. The nut is a circular-cylindrical or prismatic hollow body of hard-elastic material, in particular plastic. A protrusion, which is integrally formed with the nut body, projects from the inner wall of the hollow body and it is oriented obliquely towards the axis. The free end of the projection cooperates with the thread of the bolt such that the threaded bolt is axially displaceable in one direction relative to the nut, causing elastic deformation of the protrusion. In the other direction, the is locked, but it is threadable similarly to a conventional, rigid nut and a force can be transmitted in the axial direction between the threaded bolt and the nut The protrusion is formed with an axial extension, which extends to approximately the plane of the contacting surface of the nut with the component to be clamped in the fastener assembly.