A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6145-00-011-2390
NSN 5935-01-516-0319
NSN 5975-00-350-8151
NSN 4140-01-298-5651
NSN 5990-00-789-1333
NSN 6150-01-458-7719
NSN 5960-01-298-4143
NSN 6645-01-470-0635
NSN 7035-01-561-8738
NSN 2925-01-497-9381
NSN 6135-00-676-5807
NSN 6110-00-103-9358