A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5996-01-364-4879
NSN 6610-01-200-6861
NSN 5996-01-304-3732
NSN 5965-00-913-9545
NSN 5975-01-273-0209
NSN 5910-01-025-4500
NSN 6620-00-345-3456
NSN 5925-01-433-3952
NSN 5925-01-371-2876
NSN 5945-00-077-8270
NSN 5925-01-615-8626
NSN 5960-01-481-3722