Re-usable two-piece blind fastener

Abstract

A re-usable two-piece fastener for releasably clamping two workpieces together comprises an expandable hollow plastic body for receiving an axially insertable and rotatable screw made of plastic or metal. The body comprises a slotted outwardly expandable shank having a head or flange at its outer end and a bore extending entirely through the body. The screw comprises a threaded shank having a head at its outer end. The body bore comprises an outer end portion of the same diameter as the threaded screw shank, an intermediate thread-engaging member having an aperture of the same diameter as the root diameter of the screw shank and sloped at the same pitch as the screw thread, and an inner end portion. The thread-engaging member may be integral with the body or may take the form of a metal insert. The inner end portion of the body bore may be of the same or larger diameter than the screw thread or may be of smaller diameter so that the screw thread can self-tap thereinto. The screw, if plastic, may have a slot at the inner end of its shank so as to provide inwardly flexible bifurcations to facilitate initial axial insertion of the inner end of the screw through the thread-engaging portion. The underside of the screw head of a plastic screw or the underside of the body flange, or both, may be provided with an integrally formed annular flexible seal and the body flange may have two such seals.