RIVET (O. Fr. rivet, from river, to fix, fasten together, of unknown origin; Skeat compares Icel. rifa, to stitch together), a metal pin or bolt used to fasten metal plates together. A rivet, made of wrought iron, copper or other malleable substance, is usually made with a head at one end, the other end being hammered out after passing through the plates so as to keep them closely fastened together. A “bolt” differs from a rivet in that one or both ends have screw-threads to hold a nut (see Shipbuilding).