A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5950-01-444-1302
NSN 6105-01-293-9346
NSN 5925-00-246-4645
NSN 5960-01-142-1995
NSN 6320-01-165-8932
NSN 6130-01-506-0101
NSN 6145-00-515-6931
NSN 6620-01-142-8277
NSN 5855-01-285-3483
NSN 6110-00-409-7019
NSN 6685-00-483-2982
NSN 7035-01-134-7080