A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5999-00-213-4269
NSN 7035-01-271-1643
NSN 5855-00-944-0949
NSN 6130-01-281-7268
NSN 5930-01-634-0659
NSN 6220-01-371-1058
NSN 5920-00-224-4393
NSN 4140-00-185-2993
NSN 6610-00-242-3160
NSN 6240-00-774-9302
NSN 5975-01-642-5275
NSN 5998-00-081-1454