A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6150-01-065-0481
NSN 5996-01-292-7588
NSN 6130-01-315-4165
NSN 5925-00-337-8138
NSN 5999-01-254-2651
NSN 5930-01-388-9709
NSN 6610-01-415-5877
NSN 6130-00-556-2027
NSN 6320-01-352-5653
NSN 6105-00-672-5891
NSN 5965-00-630-7872
NSN 5905-01-120-7344