A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5990-01-551-4356
NSN 6620-01-338-2995
NSN 5996-01-382-5113
NSN 5990-00-909-2154
NSN 4140-01-445-1647
NSN 6110-01-068-0301
NSN 5930-01-437-5891
NSN 6320-00-564-2772
NSN 5990-01-131-2008
NSN 5985-01-159-2434
NSN 5965-01-364-1232
NSN 7035-00-727-4068