Nas523 Rivet Code Chart ⟶

Using this standardized system prevents structural failure by ensuring technicians don't accidentally swap materials or head styles. For example, universal heads (AN470) are used for maximum strength, while countersunk heads (AN426) are reserved for low-drag external surfaces.

For detailed installation guides and technical measurements, technicians often refer to resources like the NAS523 Solid Rivet Specifications or official AIA/NAS standards . NAS523 Rivet Identification Guide | PDF - Scribd

| Dash No. (Diameter) | Shank Diameter (inches) | Dash No. (Length) | Length (inches) | |---------------------|-------------------------|-------------------|------------------| | -3 | 3/32” (0.094) | -4 | 4/16 = 0.250” | | -4 | 1/8” (0.125) | -5 | 5/16 = 0.312” | | -5 | 5/32” (0.156) | -6 | 6/16 = 0.375” | | -6 | 3/16” (0.188) | -7 | 7/16 = 0.437” | | -7 | 7/32” (0.219) | -8 | 8/16 = 0.500” | | -8 | 1/4” (0.250) | -10 | 10/16 = 0.625” | Nas523 Rivet Code Chart

For example, a mechanic looking at a technical drawing might see a callout for "MS20470AD4-4." To the uninitiated, this is gibberish. To a professional trained in NAS523, this code immediately reveals:

False. The dash number after diameter indicates total length , not grip. Grip = total length – (clinch allowance + head height). For universal head rivets, grip is approximately total length minus 1.5 × shank diameter. NAS523 Rivet Identification Guide | PDF - Scribd | Dash No

The is a symbolic system used on aircraft blueprints and assembly drawings to specify exactly which fasteners to use and how they should be installed. Instead of long text descriptions, engineers use a four-quadrant "crosshair" symbol that technicians must decode to identify rivet part numbers, materials, sizes, and installation methods. The Four Quadrants of the NAS523 Symbol

: Contains a code for the part number (e.g., AN or MS) and the alloy. Upper Right Diameter & Placement : Specifies rivet diameter in To a professional trained in NAS523, this code

Most common alloy, identified by a single dimple on the rivet head.

This is the critical section where the NAS523 system shines. It uses one or two letters to designate the chemical composition of the rivet. This tells the mechanic immediately if they are working with a standard aluminum rivet or a high-strength corrosion-resistant steel rivet.

The general structure usually follows this pattern: