Abstract: A clamping device for clamping a panel to a supporting flange comprises a clamping element with a radial arm for engagement with the lower side of the flange. The clamping element is mounted on one end of a rotatable pin by means of a cross-pin passing through the rotatable pin and engaging grooves in the clamping element. The rotatable pin has a head with a slot for turning the pin. The head is mounted within a cup and biassed away from the base of the cup by a spring which holds the cross-pin in engagement with the clamping element. The cup fits in an aperture in the panel and has a flange at its open end which rests against the face of the panel. A washer fixed to the underside of the panel has a rib which engages locating recesses in the clamping element.