BOLTS, in a ship, are iron pins, of which there are several sorts, according to their different makes and uses. Such are drive-bolts, used to drive out others. Ray-bolts, with jags or bars on each side, to keep them from flying out of their holes. Clench-bolts, which are clenched with rivetting hammers. Forelock-bolts, which have at the end a forelock of iron driven in to keep them from starting back. Set-bolts, used for forcing the planks, and bringing them close together. Fend or fender bolts, made with long and thick heads, and struck into the uttermost bends of the ship, to save her sides from bruises. And ring-bolts, used for bringing to of the planks, and those parts whereto are fastened the breeches and tackle of the guns.