A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 4140-01-204-7025
NSN 6110-00-820-1660
NSN 5935-01-421-9819
NSN 5855-01-593-7384
NSN 6150-00-205-6775
NSN 5920-00-265-0003
NSN 5996-00-836-7393
NSN 5960-00-005-2424
NSN 5985-00-767-6315
NSN 5895-00-539-8322
NSN 5905-00-581-4592
NSN 6645-01-163-9930