A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6685-01-220-9354
NSN 6240-01-469-7324
NSN 5999-01-442-8662
NSN 6150-01-337-9782
NSN 6150-00-127-7816
NSN 7035-01-333-9298
NSN 6135-01-424-8130
NSN 6150-01-218-0746
NSN 5950-01-195-2927
NSN 6110-01-354-2885
NSN 5975-01-486-0426
NSN 5998-01-613-7954