A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5905-01-067-8360
NSN 5998-01-513-2977
NSN 5855-01-279-5316
NSN 5996-01-214-6575
NSN 5950-01-619-0819
NSN 5996-01-253-1404
NSN 6220-00-338-1086
NSN 6105-00-377-8206
NSN 5930-00-945-0135
NSN 4140-00-229-8553
NSN 4140-01-298-5651
NSN 5985-01-088-3903