Boss thread is 7/8-14 and the flare thread is 3/4-16
An adapter having machine threads (straight threads other than pipe or hose series) designed to accommodate a tube on one end or an unthreaded end designed to accommodate a tube. 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 tube or tube 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, tube and nipple, tube.
NSN 4140-01-607-4309
NSN 2925-00-779-3410
NSN 5920-01-394-0636
NSN 6320-00-845-3261
NSN 6130-01-294-3984
NSN 6610-01-158-6540
NSN 6145-01-249-9698
NSN 6105-00-005-8505
NSN 5996-01-340-6136
NSN 5999-01-606-6004
NSN 5990-00-474-5609
NSN 6220-01-285-0199