A washer having a centrally located hole with a solid or laminated cross-section and two flat parallel bearing surfaces. The hole must be 75 percent or less than the largest dimension and the bearing surface finish is greater than 32 microinch (0.8 micrometer). The thickness cannot exceed 25 percent of the largest outside dimension. When the largest outside dimension is less than 1/4 inch or 6mm, the thickness must be 0.006 inches (0.15mm) or greater and for items 1/4 inch (6mm) or larger, the thickness must be 0.016 inches (0.4mm) or greater. The maximum tolerance is applied to dimensions and used as a determining factor. Items with separable lamination use shim. For items fabricated from ceramic or electrically rated materials by specification or industry standards use insulator (1), washer. Excludes disk, valve, graphite impregnated and lubricated items.
Dept. of the Navy 
Italy 
Turkey Classification: Gaskets, washers and other seals, of vulcanized rubber other than hard rubber
NSN 6135-01-400-2947
NSN 5985-01-153-2657
NSN 5915-00-709-0068
NSN 2925-01-507-4797
NSN 7035-01-327-4017
NSN 5855-01-351-6277
NSN 6240-01-411-5630
NSN 6240-01-537-8794
NSN 5835-00-102-2373
NSN 5895-00-056-1512
NSN 6645-01-010-3746
NSN 5925-01-056-5127