A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5905-01-348-7785
NSN 5855-00-058-1293
NSN 6105-01-167-0758
NSN 5895-00-156-4513
NSN 6145-01-576-9609
NSN 6645-01-089-6459
NSN 4140-00-388-6829
NSN 5965-00-564-4399
NSN 2925-01-330-2988
NSN 6610-00-480-4898
NSN 6650-00-526-7785
NSN 4140-01-130-1456