Abstract: A pair of companion hardware parts are connected together by a screw in order to close a link for webbing components of a drag chute or the like. One of the parts provides a threaded hole for the screw and the other of the parts provides a recess for accommodating the head of the screw and also provides an access opening for passage of the screw shank for engagement with the threaded hole. A spring retainer is detachably received in an internal groove of the recess. The retainer has a key that interfits keyways in the screw head and the recess whereby the screw is locked in place notwithstanding vibration and shock. No part of the mechanism projects beyond the recess. Hence it cannot catch or snag. Desirably a tang extends diagonally from the retainer in order to block access to the screw to inhibit attempted removal by an untrained or unauthorized person.