A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6320-01-384-3850
NSN 5895-01-090-7564
NSN 6320-00-194-4252
NSN 4140-00-855-7532
NSN 5915-00-271-2321
NSN 5930-01-514-3565
NSN 5895-00-543-2906
NSN 6240-01-139-3377
NSN 6645-01-381-2050
NSN 6650-01-204-7841
NSN 6220-01-272-9239
NSN 5999-00-468-2470