The system uses a symbolic "cross" located on blueprints to give technicians immediate instructions for a specific location: Part number and material alloy code.
Often identifies an MS20426AD rivet (countersunk 2117 alloy). ↗️ Northeast (NE): Diameter & Head Placement nas523 pdf
The NAS523 code is a standardized practice that includes all types of fasteners that undergo permanent deformation during installation. Removing these fasteners typically requires their destruction, making precise initial installation essential for structural integrity. The system uses a symbolic "cross" located on
Often identifies an MS20470AD rivet (2117 aluminum alloy). particularly solid rivets.
The (National Aerospace Standard 523) is a vital fastener coding system used throughout the aviation industry to standardize the identification and installation of permanent fasteners, particularly solid rivets. This system simplifies complex engineering drawings by consolidating critical data—such as part numbers, diameters, material alloys, and hole preparation methods—into a single four-quadrant "crosshair" symbol. What is the NAS523 Fastener Code?
Fastener diameter and manufacturer head location.