Abstract: This disclosure relates to a pre-assembled fastener assembly having a retainer, a nut member, and a cold expansion mandrel that is forcibly removable after the assembly is installed into an opening of a structural workpiece. The mandrel is captured between a portion of a retainer and a portion of a nut member. The forced removal of the mandrel expands the retainer into the opening, securing the fastener assembly therein. The assembly may also include a cap coupled to the retainer to seal the opening in the structural workpiece. The nut member can be fixed or free-floating with respect to the retainer. In addition, the nut member can be threaded to receive a fastener. The mandrel is recyclable or disposable.

Abstract: An elongated first tubular member has a mandrel receiving center passageway and a slotted outer end portion that comprises first axial fingers separated by first axial slots. An elongated second tubular member surrounds the first tubular member and has a slotted outer end portion that comprises second axial fingers separated by second axial slots. An elongated third tubular member surrounds the second tubular member and has a slotted outer end portion comprising third axial fingers separated by third axial slots. An elongated mandrel is positioned inside the center passageway. The mandrel has a small diameter inner end portion, a large diameter outer end portion, and an increasing diameter portion extending from the small diameter inner end portion to the large diameter outer end portion. The third fingers have outer end portions that form an end opening. These fingers include radially inwardly projecting clamp jaws having substantially radial first clamp surfaces.

Abstract: A circular opening (48) is formed in a structural wall (12). A tubular shank (28) of a nut mounting grommet (26) is inserted into the opening (48). The grommet (26) is moved endwise to place a shoulder surface (34) on the base of a nut mounting cup (30) against the wall (12). A split sleeve (54) is installed on a small diameter portion (62) of a mandrel (52) and the mandrel and sleeve (52, 54) are inserted into the tubular shank (28) from the side of the wall (12) opposite the nut receiving cup (30). The mandrel (52) is then retracted to successively move increasing and maximum diameter portions (64, 66) of the mandrel (52) through the split sleeve (54). The mandrel portions (64, 66) exert a radially outwardly expanding force on the split sleeve (54). The split sleeve (54) in turn imposes a radially outwardly expanding force on the tubular shank ( 28).