CLEARANCE HOLE CUTTING SCREW

摘要

Disclosed is a screw for fastening semi-rigid sheet material to a substrate. The screw has a cutter arrangement (4) integrally formed with the screw shank. The cutting arrangement is for cutting in the sheet a clearance hole relative to the shank so as to accommodate thermal movement between the sheet and the shank in use. The arrangement comprises a plurality of wings (4) spaced around the axis of the shank. Each wing is inclined relative to the axis of the shank such that the end of the wing closer to the head of the screw trails the other end of the wing in the direction of driving rotation of the screw.