A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5835-01-116-2369
NSN 5895-00-990-6542
NSN 6685-01-368-1534
NSN 7035-01-386-5722
NSN 6610-00-146-3499
NSN 5835-01-101-8382
NSN 5985-01-568-2437
NSN 5965-01-343-2543
NSN 5950-01-360-5614
NSN 5915-00-541-5589
NSN 5996-00-594-8587
NSN 6220-01-185-9331