A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6110-00-311-0823
NSN 6610-01-182-9828
NSN 6105-01-375-8752
NSN 5905-01-382-0013
NSN 5950-01-487-3750
NSN 6685-00-411-2367
NSN 5999-01-076-4206
NSN 7035-01-393-6015
NSN 6105-01-361-8352
NSN 5996-00-188-7063
NSN 5999-01-419-6983
NSN 6145-01-147-4968