A self-locking knob and stud assembly includes a self-locking knob consisting of an internally threaded knob with an apertured spring retainer clip slidably received in a transverse slot provided in the knob, the aperture through the retainer clip being operative to effect a locking action of the knob relative to a stud on which the knob is threaded when rotated in one direction. The stud which is of special configuration has a reduced diameter Z-shaped free end shank portion that extends axially outward for the externally threaded portion of the stud. The aperture through the retainer clip is defined by a semi-circular rim edge at one end thereof to define an opening of a diameter so as to slidably and rotatably receive the Z-shaped free end shank portion of the stud and the aperture is defined at its other end by an edge means including a cam tab means positioned to normally be in the path of the Z-shaped shank portion during rotation of the knob relative thereto, the retainer clip further including a return bent spring portion abutting against the exterior of the knob to normally bias the retainer clip in a direction whereby the cam tab edge means is positioned to be in interference relationship with the Z-shaped free end shank portion of the stud upon rotation of the knob relative thereto.