Asde-3 military specification steel flat washer, zinc-plated, 1/2" screw size, ms-51412-28 0.500" id. Comes from vendor in package of 50; but, only need q type 1 per unit. This goes on nha asde-3 50mm belt tensioner nsn: 5840-01-319-8437, p/n 187861-201
No other part numbers with same form, fit, and function found.
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.
NSN 4140-01-360-9873
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