Patent ID: 7374381

Claim:
An assembly, comprising: a fastener joining two metal sheets in face-to-face contacting relationship, comprising; a shank having a preformed head at one end and a preformed endcap at the opposite end; the head being a first displacer having a top surface and being the largest diameter of said fastener; a first undercut groove on said shank, located immediately below said first displacer, said first undercut groove having a first diameter; a second displacer on said shank, located immediately below said first undercut groove, said second displacer having a second diameter less than said head largest diameter and larger than said 1 st diameter; a second undercut groove on said shank located immediately below said second displacer; and the endcap located immediately below said second undercut groove and being of lesser diameter than said second displacer's second diameter; a first planar sheet having a first hole therein including sidewalls which occupy substantially all of said first undercut groove of said fastener; and a second planar sheet joined in face-to-face relation to said first sheet, said second sheet having a second hole therein of lesser diameter than said first hole in said first sheet and being concentric therewith, said second hole being of lesser diameter than said first hole and having sidewalls which occupy substantially all of said second undercut groove of said fastener, said top surface of said fastener is substantially flush with a top surface of said first sheet and an endface of said endcap of said fastener is substantially flush with a bottom surface of said second sheet.