An adapter having standard hose threads on one end, an incomplete part of a threaded end connection that grips the hose directly, or an unthreaded end designed to accommodate a hose. The other end has external or internal machine threads (straight threads other than pipe or hose series) and is designed to facilitate a gasket, preformed packing, washer, or the like to form a seal at the boss. It is designed to join a hose or hose fitting to a boss or boss fitting in a straight line on items such as tanks, housings, valve fittings, and the like. See also coupling, hose and connector, hose, bulkhead. Excludes items having flanged ends.