A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5835-00-233-6327
NSN 6645-01-578-6309
NSN 6150-01-100-0932
NSN 5925-00-902-3240
NSN 6685-00-854-8402
NSN 6610-01-247-1798
NSN 6240-01-430-6937
NSN 6130-01-501-2611
NSN 6650-01-324-0351
NSN 6145-01-460-1673
NSN 5999-01-440-6144
NSN 6110-00-699-1495