A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6135-00-856-1343
NSN 6150-01-189-8556
NSN 6320-01-145-9013
NSN 5855-01-549-8494
NSN 2925-01-118-6125
NSN 5985-01-327-3601
NSN 5960-01-531-9108
NSN 6240-00-713-0237
NSN 6240-01-026-0032
NSN 5935-00-856-4192
NSN 6650-01-076-1997
NSN 5990-00-004-4158