A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5998-01-160-7996
NSN 6105-01-050-7795
NSN 6135-01-463-2445
NSN 6320-01-116-3980
NSN 6150-01-230-8060
NSN 5915-01-633-9845
NSN 6685-00-851-0515
NSN 6130-01-275-2174
NSN 6610-01-569-3385
NSN 6110-00-521-8932
NSN 6320-01-476-7702
NSN 5996-00-976-1429