A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5950-01-391-0030
NSN 6645-01-025-1002
NSN 5930-01-027-3834
NSN 5996-00-487-5777
NSN 5999-01-431-8066
NSN 6240-01-581-7737
NSN 5950-00-578-7330
NSN 5960-01-539-1956
NSN 5996-00-014-6032
NSN 5835-01-024-9249
NSN 5945-01-117-7009
NSN 5935-00-938-9432