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 6130-00-400-0786
NSN 5945-00-235-8518
NSN 5960-00-024-9783
NSN 5975-00-456-2257
NSN 5925-01-645-1891
NSN 5925-01-018-1375
NSN 6610-01-327-3187
NSN 5910-01-652-7956
NSN 6650-01-120-6231
NSN 5895-00-290-6501
NSN 5935-01-081-9399
NSN 5950-01-260-2871