A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5999-01-603-6563
NSN 6610-01-007-0268
NSN 5975-00-910-8680
NSN 5960-01-218-2858
NSN 5835-01-229-6964
NSN 5920-01-658-0197
NSN 5925-01-174-6558
NSN 6105-00-775-0387
NSN 5960-01-449-1310
NSN 6620-01-100-3181
NSN 5855-01-133-3587
NSN 5990-01-296-8190