For a nbr 10 screw
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
Classification: Spring washers and other lock washers, iron or steel
NSN 6240-01-518-3874
NSN 5930-00-340-2932
NSN 5990-01-270-3209
NSN 6110-00-443-9624
NSN 5905-00-803-9858
NSN 5975-01-391-7127
NSN 2925-00-504-2363
NSN 6610-01-283-8888
NSN 6110-00-126-8402
NSN 2925-01-481-7170
NSN 6320-00-725-0754
NSN 6610-00-357-2937