Abstract: A collar stud assembly for attachment to a plastic boss having a bore therein comprises a double-ended fastener and a sheet metal cap. The double-ended fastener has a shank with a first thread suitable for threading into plastic on one end thereof, a second thread adapted to threadingly engage a nut or other threaded member on the other end thereof and a collar integral with the shank between the first and second thread for limiting the threading movement of the fastener into the bore of a plastic boss. The shank extends beyond the first thread and includes a raised ring at the end of the first thread for holding the metal cap in position for seating on a plastic boss and a knurl which is spaced from the end of the first thread and which provides a shoulder upon which the metal cap rests. The metal cap is adapted to fit over the end of a plastic boss and the top of the cap is captivated on the land of the shank between the knurl and raised ring.