Standard or part number (e.g., "BJ" for a specific rivet type). Diameter & Head
This quadrant uses a two-letter code to represent the industry specification (like Military Standards (MS) or National Aerospace Standards (NAS) ) and the material alloy. BJ: MS20470AD (Universal head, 2117 aluminum). BB: MS20426AD (100° Countersunk head, 2117 aluminum). 2. Northeast (NE): Diameter & Head Side nas523 rivet code pdf
For flush riveting, the PDF includes the exact radius and depth of the 100° countersink. A mismatch between the rivet head and the countersink angle creates a stress riser. The NAS523 PDF includes go/no-go gauge dimensions. Standard or part number (e
The NAS523 symbol is a simple cross, but each corner (quadrant) is designated with a "compass" position—though these designations (NW, NE, SW, SE) are usually not printed on the drawing itself. Northwest (NW) – Head Style & Alloy : This quadrant identifies the rivet part number (such as standards) and its material. For example, the code BB: MS20426AD (100° Countersunk head, 2117 aluminum)
In the world of aerospace manufacturing and maintenance, a single point of failure is not an option. Every rivet, bolt, and screw must meet stringent military and industry standards. Among the thousands of fastener specifications, the standard stands out as a critical reference. However, for engineers and technicians, finding a usable, searchable, or printable NAS523 rivet code PDF has historically been a challenge.
NAS523 Rivet Code is a standardized symbolic system used in aviation engineering drawings to provide precise instructions for fastener installation. It uses a single "crosshair" symbol divided into four quadrants, each representing specific rivet data. Quadrant Breakdown
The is a standardized aerospace identification system used on engineering drawings to specify the exact type, size, and installation requirements of fasteners through a single four-quadrant "cross" symbol. This system allows technicians and engineers to communicate complex assembly instructions—such as head style, material, diameter, and hole preparation—without cluttering blueprints with text. Structure of the NAS523 Symbol