Abstract: A self-pierce rivet includes a shank and a head at one end of the shank. The other end of the shank of the rivet is provided with an axially extending slot. The head is non-circular and is formed with substantially mutually perpendicular major and minor dimensions, the minor dimension of the head extending substantially parallel to the slot. The shank of the rivet may be provided with a central hole extending from the free end of the shank towards the head. The head of the rivet may be substantially rectangular.

Abstract: Tools (3, 4) mounted on the free ends of the arms of a C-frame applicator are aligned by providing the arms of the C-frame (1) in a form which is capable of flexing between a first position in which the axes of the tools (3, 4) are disposed at an angle relative to each other and a second position in which the axes of the tools are coaxial with each other. A workpiece (6) is arranged between the tools and a predetermined clamping load is applied to the workpiece (6) sufficient to flex the C-frame (1) from the first position towards the second position and bring the tools (3, 4) substantially into coaxial alignment. One or more of the tools (3, 4) is then actuated to apply a force to the workpiece (6).

Abstract: A mounting mechanism for mounting a fastener applicator on a positioning mechanism. The mounting mechanism incorporates fluid actuators for applying compensating forces and turning moments that counteract the effects of the applicator weight by bringing the forces and turning moments into substantial equilibrium or predetermined directional bias so that the applicator is movable by a minimal force. The fluid actuators thereby enabling final correction of the applicator position and orientation prior to fastener application by movement of the fastener applicator relative to the position mechanism as a result of contact between the applicator and the workpiece.

Abstract: In convention lug caps or pre-threaded caps to be screwed onto a threaded neck ring of a bottle or jar, it sometimes happens that the lugs or threads become hooked under the threads during application of the cap. This can lead to damage to the lugs or threads and failure of the closure. According to the invention, a lug cap or pre-threaded cap is provided with a formation such as a wall to prevent the cap being applied to the neck of the bottle when such hooking is threatened.