A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6620-00-568-3947
NSN 5998-01-417-2638
NSN 6610-01-472-8876
NSN 5855-01-615-1505
NSN 6150-01-599-9429
NSN 6645-00-081-4298
NSN 4140-01-299-6713
NSN 6650-01-320-1169
NSN 6145-00-350-9285
NSN 6620-01-567-7456
NSN 6685-01-420-0410
NSN 5996-00-267-1139