This is a 5/16 inch stainless steel lock washer quani type 10
No other part numbers with same form, fit, and function found.
A washer which is usually round with a centrally located hole. Its edges and two bearing surfaces are so designed that applied pressure brings into play the spring tension and/or frictional locking principle which materially resists any tendency toward turning. It may be made of one or two pieces
NSN 6150-01-657-8909
NSN 6135-00-819-8074
NSN 5905-01-068-2955
NSN 5990-00-036-6449
NSN 6650-01-555-8349
NSN 5950-00-079-0159
NSN 5920-01-596-7297
NSN 5950-01-645-6811
NSN 2925-01-172-9209
NSN 5920-01-017-3233
NSN 5915-01-008-3547
NSN 6685-01-415-9228