A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5910-00-101-8273
NSN 5985-01-264-2344
NSN 6150-00-218-0891
NSN 6150-01-012-3107
NSN 6650-00-495-8710
NSN 7035-00-620-6835
NSN 5945-01-284-8977
NSN 5950-01-656-4167
NSN 5915-00-653-9457
NSN 5925-00-630-8178
NSN 5950-01-127-8677
NSN 6145-01-072-9251