A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6130-01-379-6372
NSN 7035-01-302-5359
NSN 6320-01-607-1491
NSN 5999-01-106-3451
NSN 6320-00-925-0558
NSN 5950-00-280-7825
NSN 5935-01-448-0195
NSN 6685-01-421-4403
NSN 5915-01-382-0517
NSN 4140-00-733-7936
NSN 5920-01-115-1739
NSN 6135-00-767-0331