Patent ID: 7341395

Claim:
A combinational bolt which includes: a screw unit that has a plurality of threads formed on an external surface of a front terminal end portion of the screw unit for coupling with a first target object, the screw unit having an annular first concave portion formed therein adjacent a rear terminal end portion thereof; and a longitudinally extended sleeve unit set inside an opening formed in a second target object, the sleeve unit having a longitudinally directed bore formed therein for receiving the screw unit therein to join the first target object to the second taget object, the sleeve unit having a sink-proof portion formed on an external surface thereof adjacent an open terminal end of the sleeve unit, the sink-proof portion of the sleeve unit clampingly engaging the second target object, the sleeve unit having a plurality of strengthening circle units formed thereon, a second concave portion forming an annular convex protrusion within the bore of the sleeve unit for clampingly engaging the first concave portion of the screw unit, and a plurality of cut slots formed through a wall of the sleeve unit and extending longitudinally from the open terminal end to a location beyond the second concave portion.