The PDF contains detailed tables for various dash numbers. For example, a typical NAS523 washer will specify:

: Represents the MS20426AD (100° Countersunk Head, 2117 aluminum alloy).

Specifically, is titled: “Fastener, Captive Washer, Non-Metallic, Assembly, Procurement Specification.” However, in practical industrial use, the standard is most famously associated with the requirements for threaded fasteners and lock washers , particularly regarding plating, lubrication, and dimensional conformity.

The final number, usually separated by a dash, indicates the total grip length of the rivet, measured in . -4 = 4/16" (1/4") long -6 = 6/16" (3/8") long -8 = 8/16" (1/2") long

"B1" represents a standard MS20470AD rivet made from 2117 aluminum alloy. 2. Northeast Quadrant (NE) - Diameter and Head Location