Two raised dashes on the head. Also an icebox rivet, offering high strength.
The letters immediately following "NAS523" represent a combined code for the specific rivet standard and material. For instance: : Can represent an MS20470 (universal head) rivet. BB : Can represent an MS20426 (100° countersunk) rivet.
Interpretation: This code corresponds to a protruding head rivet (likely a universal head type). The diameter code of 5 gives a diameter of 5 × 1/32 inch = 0.15625 inch (approximately 5/32 inch). The "F" indicates the manufactured head is to be installed on the far side of the assembly. The blank lower left quadrant confirms that no countersinking or dimpling is required (consistent with a protruding head rivet). The length code of 8 corresponds to the designated grip length.
7050 Aluminum Alloy (High strength; features a raised cross). nas523 rivet code pdf
The 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
The NAS523 code is traditionally structured around a cross symbol on engineering drawings, or written as a continuous text string in digital inventory systems. The callout is divided into four quadrant positions, each representing a specific characteristic of the rivet. 1. The Specification/Standard (The Base Code)
I can’t provide copyrighted PDFs directly. For authoritative copies: Two raised dashes on the head
The Ultimate Guide to the NAS523 Rivet Code: Understanding Aerospace Fastener Symbols
This public link is valid for 7 days and shares a thread, including any personal information you added. This link or copies made by others cannot be deleted. If you share with third parties, their policies apply. Can’t copy the link right now. Try again later.
The NAS523 standard has undergone several revisions (e.g., Rev 5 vs. Rev 8). Changes have included: For instance: : Can represent an MS20470 (universal
Using NAS523 codes prevents manufacturing errors, streamlines procurement, and ensures that mechanics and automated riveting systems install the exact fastener required for flight safety. The NAS523 Rivet Symbol Structure
Universal head rivets, used in internal structures where aerodynamics are not a factor.
The NAS523 code is a standardized system defined by National Aerospace Standards (NAS) to represent rivet specifications on engineering drawings using a simple cross-shaped symbol. Instead of writing out lengthy part numbers, materials, lengths, and locations for every single fastener, engineers use this universal shorthand.