6 Metal fasteners, namely, rivets and rivet nuts, bolts, weldable studs, brackets and clips; metal nuts and metal nut fasteners, namely, self-locking nuts, weld nuts, clinch nuts, cage nuts and washers; metal screws, namely, self-tapping and self-drilling screws, thread forming screws, and screw and bolt anchors; metal hardware, namely, screw connections and parts of screw connections, namely, thread inserts, expansion inserts and sleeves, clinch inserts, flange inserts, screw thread inserts, pipe thread inserts, screw thread bushings, spark plug screw thread helical inserts and bushings; and metal hardware, namely, gages for use in screw connections with or without wire thread, namely, screw thread gages and flush gages