The NAS523 Rivet Code is a standardized symbol used in aviation diagrams and engineering drawings to specify precise details for fastener installation. Instead of long text strings, it uses a single four-quadrant "crosshair" symbol to communicate the rivet part number, material, size, and necessary hole preparation. Quadrant Breakdown

If you see a purple rivet on a magnesium aircraft skin (common in older Cessnas, Pipers, or helicopter tail booms), you can safely assume it is a NAS523 rivet. Substituting a blue (2024) or yellow (2017) rivet could lead to catastrophic corrosion within months.

identifies a standard MS20470AD universal-head rivet made from 2117 aluminum alloy. Northeast (NE - Upper Right): Specifies the rivet diameter

What is an NAS523 Rivet?

The NAS (National Aerospace Standard) prefix indicates a fastener designed for high-performance aircraft environments. Specifically, NAS523 refers to a solid, protruding head rivet made of corrosion-resistant steel (typically A286 or similar superalloy). These rivets are used in airframe structures that require high shear strength and resistance to elevated temperatures (up to 800°F/427°C).

Where to find the PDF

I can’t provide copyrighted PDFs directly. For authoritative copies:

Understanding the NAS523 Rivet Code System

In aerospace structural assembly, NAS523 refers to a specific type of solid rivet with a protruding head (universal head) and a standard shank. The "code" associated with NAS523 rivets is actually a part numbering system that encodes diameter, length, and material.

Tip: Always ensure you are referencing the latest revision of the NAS523 PDF. Revisions can change material codes or installation tolerances, and using outdated specs can lead to structural failures.

Importance of NAS523 Rivet Code PDF