A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5965-01-308-2261
NSN 5835-01-064-0261
NSN 5920-00-493-8307
NSN 5985-01-512-1867
NSN 6685-01-168-3793
NSN 5975-01-606-8269
NSN 5930-01-338-1196
NSN 5915-01-222-7504
NSN 5960-01-481-8051
NSN 5920-01-463-8484
NSN 6105-01-617-0251
NSN 5999-01-231-9728