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 
Canada 
Italy 
Turkey Classification: Gaskets, washers and other seals, of vulcanized rubber other than hard rubber
NSN 5855-01-631-5051
NSN 6645-00-913-2723
NSN 5975-01-432-4519
NSN 5998-00-944-9594
NSN 5905-01-381-7943
NSN 5910-00-153-6612
NSN 2925-01-265-2853
NSN 5855-01-041-9392
NSN 6645-00-551-8291
NSN 6610-01-535-0310
NSN 5975-00-067-5236
NSN 5935-01-072-2293