A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5905-00-461-3187
NSN 6685-01-052-7482
NSN 5998-00-804-9956
NSN 5930-00-633-8008
NSN 6145-00-929-9406
NSN 6130-01-094-5599
NSN 5905-00-837-3204
NSN 5910-00-269-4755
NSN 5835-00-949-3018
NSN 5999-00-137-6062
NSN 5910-01-032-0091
NSN 5999-01-286-0742