A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5855-01-085-5354
NSN 5950-00-824-1728
NSN 6135-00-497-0491
NSN 5965-00-243-6420
NSN 5925-01-630-9832
NSN 6610-01-096-4601
NSN 6240-00-231-0761
NSN 5965-00-934-3495
NSN 5975-00-644-4972
NSN 6130-00-504-2956
NSN 5950-00-739-4779
NSN 5965-01-446-4386