Material is gunmetal
An item with internal machine threads designed to fit the external machine threads of a tube fitting. It has flat faces, one of which has a counterbored recess to accommodate packing, packing or sealing ring(s), gasket(s), and the like. The item, when installed, provides a method of locking and sealing the connection. See also locknut, pipe; nut (1), tube coupling and nut (1), plain, hexagon.
NSN 6320-00-456-2092
NSN 6240-00-256-6410
NSN 2925-00-051-1467
NSN 5895-00-814-7954
NSN 5920-01-643-5197
NSN 5975-00-974-6704
NSN 5855-01-523-8926
NSN 4140-01-399-3027
NSN 4140-01-381-0099
NSN 5960-01-499-7172
NSN 6135-01-555-4283
NSN 5930-01-382-1738