| 摘要 |
A screw-threaded fastener 10 includes a head 12 having top surface 32 contoured (at 34) for interlocking engagement with a driver, a threaded shank 14 extending from the clamping surface 36 and a moisture-impervious cover 16 which overlies the head portion 12 and extends axially away from the clamping surface 36 to form a flange 42 for sealing the fastener 10 to a workpiece surface into which the fastener is driven. The flange 42 is inwardly deformable upon contacting the work piece surface so as to deflect work piece fragments, produced as the fastener is driven into the work piece, away from the seal between the flange 42 and the work piece surface to preclude the fragments from interfering with the seal. A cavity 44 receives the work piece fragments as the flange is deformed. <IMAGE> |
