A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5910-01-362-7866
NSN 6105-01-089-6768
NSN 5915-01-142-8716
NSN 6610-01-342-0889
NSN 6135-01-348-2410
NSN 6110-00-395-7040
NSN 5930-01-440-9887
NSN 4140-01-351-9960
NSN 7035-01-287-9817
NSN 6610-01-250-9327
NSN 5950-01-630-3193
NSN 5895-00-504-7187