Abstract: A screw having in its head a recess that includes two or three non-circular superimposed recess-tiers. The depth of each recess-tier is less than 1.35 mm and there is less than 1° draw in each recess. The screw head recess is formed using a punch (10) in a cold heading process. The punch is formed in a profilating CNC machine, cutting the profiles of the punch to a tolerance of better than ±0.0025 mm.

Abstract: A fastener system comprises a plurality of ranges of size of threaded fastener, each fastener having a head provided with a recess to receive a tool to rotatingly drive the fastener. In each range of sizes, the largest size of fastener has a recess comprising a plurality of driving recess tiers of reducing size superimposed on one another. The range of fasteners to be driven by the tool includes a first fastener whose recess is shaped to be drivingly engaged by at least the third and second smallest tiers of the tool, but not the smallest tier. The recess receiving the second smallest tier of the tool is deep enough to freely accommodate the smallest tier.

Abstract: The screw has two or three non-circular super-imposed recesses. The depth of each recess is less than 1.2 mm and there is a less than 1° of draw in each recess. The screw head recess is formed using a punch (10) in a cold-heading process. The punch is formed in a profilating CNC machine, cutting the profiles (12,14,16) of the punch to a tolerance of better than ±0.025 mm. A method of manufacture of a cold-forming punch for such a screw comprises providing a profilating head as one of the tools on a turret mounted adjacent the chuck in the CNC machine. The profilating head has several cutting elements, each being adjustable with respect to one another: axially, radially and angularly.

Abstract: A fastener system comprises a plurality of ranges of size of threaded fastener (10), each fastener having a head (12;32) provided with a recess (14) to receive a tool (20) to rotatingly drive the fastener.

Abstract: Fastener (1) having a driving head (2) which includes at least two superimposed non-circular recesses (3, 4, 5) for receiving the bit of a driver (7) with which driver a torque can be applied to operate the fastener (1), characterised in that the fastener (1) comprises a security feature whereby said torque needs to the applied to at least two of said recesses (3, 4, 5) in order to operate the fastener (1).

Abstract: The screw has two or three non-circular super-imposed recesses. The depth of each recess is less than 1.2 mm and there is a less than 1° of draw in each recess. The screw head recess is formed using a punch (10) in a cold-heading process. The punch is formed in a profilating CNC machine, cutting the profiles (12,14,16) of the punch to a tolerance of better than ±0.025 mm.