A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5996-01-642-4224
NSN 6145-00-156-4394
NSN 5930-01-207-4900
NSN 4140-00-304-2803
NSN 6240-00-569-5854
NSN 5998-01-419-8131
NSN 5985-01-290-2615
NSN 5835-01-555-4262
NSN 5996-00-259-0309
NSN 5910-00-912-0010
NSN 6645-00-363-9775
NSN 5925-00-205-2767