Deck screws suitable for use with composite lumber

Abstract

The present invention is directed to a deck screw intended for use with composite lumber, although it can be used with other wood products, such as pressure treated lumber. The deck screw of the present invention may be provided with a head and a shaft that has two regions of varying diameter. The upper region has threads that exceed the number of threads of the lower shaft, on a unit length basis. The threads of the upper shaft may be configured in an inverted buttress design. The lower region of the shaft terminates at a tapered distal end having a pointed tip that leads the screw through the wood material. Threads are provided on the lower region of the shaft. The head of the screw is provided with an upper surface, a lower surface, and a crown that extends around the perimeter of the head, The crown extends beyond the lower surface of the head, forming a recessed region between the lower edge of the crown and the shaft of the screw. The head may also be provided with an undercut. Further, the head of the screw may be provided with a square driver opening that permits the persons installing the screw to use a square bit. For instance the opening may be a #2 square driver opening. It should be understood that Phillips heads or flat heads in various sizes might also be employed.