A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 2925-01-472-4423
NSN 6320-01-119-3935
NSN 5950-01-464-4196
NSN 6320-01-420-0340
NSN 5975-00-689-5129
NSN 5910-00-778-2383
NSN 6240-01-327-7269
NSN 5895-01-660-0847
NSN 5855-01-083-9053
NSN 5835-01-056-4149
NSN 5910-00-079-9249
NSN 2925-01-458-5808