A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5965-00-191-6788
NSN 6135-01-156-4627
NSN 5915-01-139-3162
NSN 2925-00-516-8841
NSN 6135-00-683-0536
NSN 5950-01-351-6978
NSN 5855-00-477-9943
NSN 5920-00-351-7699
NSN 6650-00-361-8222
NSN 5999-00-842-5419
NSN 5945-01-623-4534
NSN 5905-01-141-6633