Flare Lock Fastener

A shouldered hollow screw and threaded sleeve assembly, designed to be fastened in place by turning the screw, causing one end of the sleeve to flare over the shoulder and against the material through which it has been inserted. Also, a countersunk head hollow screw and flared sleeve-nut assembly, designed to mate with a dimpled hole in the material to which it is fastened. The hollow screws may also have internal threads for attaching screws. See also shield, expansion.