<p>A screw for securing dense wood material has a head with a specially configured drive socket and an underside with an array of lobes. The lobes preferably have a left-handed orientation and have chamfered extremities. The shank is specially configured with an upper thread, an intermediate unthreaded portion and a lower thread which terminates with a half-point tip. In one embodiment, the upper thread major diameter is slightly smaller than the major diameter of the lower thread. The upper thread has a greater thread density than the lower thread. The upper to lower thread-per-inch density is preferably in the range of 1.3:1 to 1.7:1. The screw is specifically configured to assist in applications where there are wet fibers near the wood deck surface.</p>
申请公布号
CA2885470(A1)
申请公布日期
2014.04.17
申请号
CA20132885470
申请日期
2013.10.09
申请人
HANDY & HARMAN
发明人
PIECIAK, JOSEPH A., JR.;BELINDA, RICHARD L.;MAZIARZ, MICHAEL W.;WEISS, TAD A.