A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6105-00-073-9392
NSN 6130-00-847-8040
NSN 5945-00-768-8615
NSN 6685-01-141-9823
NSN 6145-00-999-6680
NSN 5998-01-052-6214
NSN 6645-01-023-8724
NSN 6650-00-266-6808
NSN 5935-00-080-3031
NSN 5895-01-271-7215
NSN 5930-01-186-4841
NSN 5950-01-500-3373