Screw

Abstract

A fastener for securing remnant-producing materials, a method of manufacturing the fastener, and a method of using the fastener are provided. The fastener is configured such that in use any remnants or slivers produced by rotation of the fastener are forcibly driven into the surface of the material. In one aspect, the fastener has two separate threaded portions, a first or lower threaded portion and a second or upper threaded portion. The threads on the lower threaded portion have a pitch that is different from the threads on the upper threaded portion. In one embodiment, the lower threaded portion threads have a larger pitch than the threads on the upper threaded portion. In use, after the lower threaded portion is completely inserted into the material, the upper threaded portion of the fastener enters the material. Because the upper threaded portion has threads that have a pitch that is different from the threads on the lower threaded portion, the threads on the upper threaded portion capture the remnants that have been extruded within or onto the surface of the material. As the fastener is completely inserted into the material, the remnants that have been extruded by the lower threaded portion of the fastener are substantially retained in the bore by the upper threaded portion of the fastener.

1 . A screw comprising:
 a shank having a head end and a point end;   said shank having a first threaded section and a second threaded section, said first threaded section being closer to said point end than said second threaded section;   said first threaded section having threads that have a first pitch, said second threaded section having threads that have a second pitch, different from said first pitch;   said first threaded section having a first thread diameter, said second threaded section having a second thread diameter larger than said first thread diameter, and said head having a third diameter, said third diameter being greater than said first and second diameters; and   said first threaded section having a first thread angle, said second threaded section having a second thread angle smaller than said first thread angle.   
   
   
       2 - 13 . (canceled)