A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5935-00-578-7414
NSN 6240-00-001-1524
NSN 5925-01-169-6401
NSN 5998-00-361-8697
NSN 5960-01-064-3292
NSN 5998-01-106-2977
NSN 5990-01-386-5561
NSN 5935-00-223-6220
NSN 5905-01-514-2886
NSN 2925-00-185-1618
NSN 5915-01-584-1028
NSN 5965-01-332-6693