Abstract: A fastening clip device forming a nut in the form of a resiliently deformable U section adapted to be fitted by its legs onto the edge of a panel, and having a member interposed between the legs so as to hold them positively apart prior to their fitting onto the edge of the panel and being movable relatively to the legs so as to be displaceable therebetween under the action of the panel as the legs are passed over the edge surfaces thereof. At the end of the fitting operation, one of the legs is released to allow the U section to resiliently close onto the edge of the panel.