Screw

A fastener for clamping composite wood material to a base structure, comprising:

• a shank with a tapered section at one end and a clamping head at the other end, said clamping head having a clamping surface for clamping said composite wood material and said base structure;
• a first threaded section being closer to said tapered section adapted to make a bore in said composite wood material and for engaging with said base structure;
• a second threaded section, closer to said clamping head, adapted to forcibly drive remnants from the composite wood material into the bore of the composite wood material, wherein said first threaded section has threads having a first pitch and said second threaded section has threads having a second pitch smaller than said first pitch, and wherein said second threaded section has a second thread diameter, said clamping head has a head diameter, said head diameter being greater than said second thread diameter;
• and
• a transition section between said first and second threaded sections, said transition section having no threads;
• and
• a shank diameter of the first threaded section is substantially the same as a shank diameter of the second threaded section.

A fastener for composite wood material, comprising:

• a shank having a clamping head at one end and a point at the other 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 at least one continuous thread and said second threaded section having at least one continuous thread, such that a distance between adjacent crests of said at least one continuous thread of said first threaded section is greater than a distance between adjacent crests of said at least one continuous thread of said second threaded section;
• and
• said first threaded section having a first thread diameter and being adapted to form an opening in said composite wood material, thereby extruding remnants of said composite wood material, said second threaded section having a second thread diameter, larger than said first thread diameter, for driving said remnants of said composite wood material into said opening in said composite wood material, said clamping head having a third diameter, said third diameter being greater than said second thread diameter,
• and wherein said clamping head has a clamping surface for clamping said composite wood material and a shank diameter of the first threaded section is substantially the same as a shank diameter of the second threaded section.