A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 4140-01-061-2431
NSN 5960-01-139-3136
NSN 6685-01-113-0461
NSN 6650-00-848-9892
NSN 5905-00-456-4701
NSN 6145-01-357-6288
NSN 5920-01-253-9816
NSN 6135-01-226-4071
NSN 5998-01-069-2391
NSN 5925-00-015-2806
NSN 6240-01-109-4680
NSN 5855-01-245-8689