The standard establishes the uniform requirements for the procurement of specific types of captive washer assemblies. These are non-metallic washers used in conjunction with bolts and screws in environments where vibration, heat expansion, or conductivity issues are a concern.
: Specifies the rivet diameter and the positioning of the manufactured head (e.g., "N" for near side, "F" for far side). nas523 pdf
: Identifies the fastener type or material using a two or three-letter code (e.g., "BJ" for MS20470AD or "BB" for MS20426AD). The standard establishes the uniform requirements for the
The standard includes universal heads (strongest general purpose) and countersunk heads (used for low-drag applications). Reference Resources "N" for near side
