They interfere with the seating of fasteners, causing damage to fastener or the assembly itself. A rivet is a permanent mechanical fastener. The 12-spline flange screw drive has twelve splines in the fastener and tool. A nut is a type of fastener with a threaded hole. A bolt is a form of threaded fastener with an external male thread. A common example of a fastener with a tapered thread is a wood screw. The lid of the box is secured by a hook fastener. Their threads are designed to induce this friction to keep the fastener from loosening. The German word for burdock is and velcro is (= burdock fastener). Burrs in drilled holes cause fastener and material problems. The propellant acts on the piston, which then drives the fastener into the substrate. A safety wire is used to ensure proper security for a fastener. This allows greater torque to be applied to a fastener without the tool failing. Howe's device was more like an elaborate drawstring than a true slide fastener. The device served as a (more complicated) hook-and-eye shoe fastener.