A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5985-01-575-1893
NSN 6685-01-439-5388
NSN 6620-01-648-1594
NSN 6685-00-186-9190
NSN 6240-00-737-2775
NSN 5855-01-541-1361
NSN 5960-01-170-4057
NSN 5925-00-954-3212
NSN 6110-01-012-1759
NSN 5910-00-644-0296
NSN 4140-01-373-8862
NSN 5935-00-908-0671