| 摘要 |
A roofing washer useful with a fastener having a head and a shank, such as a roofing screw, and provided with an annular lip to restrain the head after the head has been driven past the annular lip. As molded from a resilient, polymeric material, the roofing washer has a plurality of discrete cavities, which facilitate radial expansion of the annular lip, and a plurality of discrete ribs, which separate the discrete cavities. In one possible embodiment, each cavity has an inner, generally cylindrical wall, an outer, generally cylindrical wall, and two end walls, each defining a plane oriented at an acute angle relative to a radial plane. In a different embodiment, each cavity has two planar walls and a curved wall.
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