A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5835-00-978-9806
NSN 5930-01-626-3816
NSN 6150-01-520-6905
NSN 5930-01-558-4714
NSN 5950-01-335-6086
NSN 5990-01-347-6080
NSN 5895-00-442-3211
NSN 5915-00-197-8610
NSN 6135-01-377-5729
NSN 5975-00-912-7977
NSN 5925-01-538-4020
NSN 6620-01-550-6059