摘要 |
A method and fastener for fastening one or more apertured members (48) to an apertured workpiece (52), an aperture (50) of the or each member (48) being aligned with an aperture (54) in the workpiece (52), the method comprising the steps of inserting a fastener (10) into the aligned apertures, the fastener (10) being formed of ductile material and having a head (14), a shank (12), and an axial bore (22) extending through the shank (12) and into the head (14), the shank (14) being circumferentially entire and being formed with an external screw-thread (18) the fastener (10) being inserted so that the head (14) engages a face of the one member (48), and the shank (12) extends through the member (48) or members and into the workpiece (52), and at least a part of the screw-thread (18) is within the workpiece (52), and then, while supporting the fastener (10) at the head (14), drawing into and entirely through the bore (22), in the direction from the tail portion to the head (14), a tapering, enlarged, mandrel head (32) capable of expanding the bore (22) and thereby enlarging the bore (22) evenly throughout its length and causing ductile radial expansion of the shank (12) sufficient to case the external screw-thread (18) to embed in the workpiece (52) and the shank (12) of the fastener (10) undergoing ductile axial reduction in length. |