A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6130-01-574-8968
NSN 5985-00-902-3940
NSN 5905-00-476-6271
NSN 6145-01-105-7872
NSN 5910-01-119-9209
NSN 6130-00-064-7238
NSN 5950-01-634-0677
NSN 5915-01-388-8339
NSN 5895-00-504-2380
NSN 5855-00-221-9435
NSN 5835-01-062-2235
NSN 6150-00-528-4175