A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5950-01-111-8904
NSN 5998-01-201-3225
NSN 5910-00-276-3187
NSN 6110-00-424-4557
NSN 6145-01-174-5268
NSN 6645-01-532-9027
NSN 5925-00-847-7725
NSN 5950-00-526-0658
NSN 5985-00-279-8507
NSN 5990-01-003-2627
NSN 5998-01-353-5600
NSN 5935-01-421-4827