Abstract: A screw threaded fastener (103) has an elongate shank (122) with a drilling tip (104) at one end and a head (123) at the other end. A screw thread extends along at least a part of the length of the shank (122). The trailing flank (116) of the thread subtends an angle (B) relative to the axis (117) of the fastener which approaches 90° and is greater than the angle (C) subtended by the leading flank (115). The screw is for use in fixing sheets of material a1 to thin metal battens (5) and the angle between the trailing flank (116) and the adjacent thin metal section (18) of the batten (9), being reduced in comparison to a conventional thread form, lessens the distorting effect of the thread on the batten (9) under relatively high pull-out loads.

Abstract: A method of securing sheet material to a support by means of a screw threaded fastener having a driving head adapted to drivably cooperate with a driving tool such that operation of the tool causes rotation of the fastener and enables the fastener to be driven into the support. The method is characterized in that a hole is formed through the sheet material by means of a drill bit attached to the driving tool so as to drivably cooperate with that tool in the same manner as the fastener drivably cooperates with the tool. The drill bit is removed from the tool after formation of the hole and is replaced by a fastener which is then driven into the support by the same tool so as to secure the sheet material to the support. The drill bit is characterized in that it has a drilling feature in the form of a substantially flat plate extending outwardly on each of two opposite sides of the rotational axis of the drill bit.