A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 7035-00-937-4970
NSN 6650-01-376-6965
NSN 6145-00-137-8228
NSN 5990-01-227-6526
NSN 6150-00-679-9203
NSN 6610-01-482-4630
NSN 5930-01-522-9169
NSN 6685-01-266-6867
NSN 5910-01-118-0439
NSN 5920-01-190-5167
NSN 5915-00-137-6175
NSN 5855-01-364-9810