A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5999-00-126-4735
NSN 6620-00-093-4186
NSN 5930-00-067-4468
NSN 6110-00-052-2655
NSN 2925-00-054-3550
NSN 6110-00-108-6478
NSN 5835-00-350-3703
NSN 5985-01-280-9541
NSN 5990-00-524-2293
NSN 6150-01-082-6246
NSN 5835-00-907-4390
NSN 6145-00-998-7609