A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6610-01-502-8868
NSN 5996-01-609-0098
NSN 5998-01-412-0928
NSN 6220-01-633-3509
NSN 5998-00-290-1856
NSN 5990-01-575-3275
NSN 5965-01-131-4078
NSN 5855-01-597-4404
NSN 6145-01-399-0188
NSN 5975-01-554-8031
NSN 6645-01-254-0489
NSN 5910-01-093-4719