A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5975-00-688-4625
NSN 5935-01-108-7125
NSN 6105-00-812-0505
NSN 6105-00-286-0694
NSN 6620-01-614-3591
NSN 5985-01-322-7105
NSN 5935-01-119-4534
NSN 6240-01-020-3440
NSN 6220-01-196-0332
NSN 6685-00-850-2369
NSN 5895-00-263-3982
NSN 6105-00-211-4577