| 摘要 |
<p>A screw fastener for fastening sheet material to a support, the screw fastener including a shank (3) having an elongate axis (2), a head (9) at one end of the shank, and a drilling tip (7, 7A) at an opposing end thereof, at least one substantially planar wing member (11, 11B) extending radially from the shank, the wing member having a peripheral reaming edge (15), and means for extending the time that the sheet material is in contact with the peripheral reaming edge of the wing member while the screw fastener is being driven through the sheet material.</p> |
