A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6145-00-168-8616
NSN 5965-00-253-1302
NSN 6320-00-894-1644
NSN 5915-00-329-6899
NSN 5960-01-582-6167
NSN 5960-01-126-6245
NSN 6130-01-550-5154
NSN 4140-01-185-6214
NSN 6220-00-053-5599
NSN 5950-01-605-6984
NSN 6645-01-076-4655
NSN 6150-01-376-2212