NAS523 is a standardized Fastener Code system established by the National Aerospace Standards Committee (NAS) to provide a universal symbolic language for identifying permanent fasteners, primarily rivets, on aerospace blueprints and engineering drawings. The code is designed to fit complex data—such as part numbers, diameters, material alloys, and specific installation requirements—into a single, four-quadrant symbol often referred to as the "rivet cross". The NAS523 Symbolic System
Length is typically calculated as the total thickness of material plus the rivet diameter protruding through the structure. Shop Head Inspection: nas523 pdf top
Unlike standard hex bolts, flange bolts (often called frame bolts) integrate a washer-like flange directly beneath the head. This design distributes the clamping load over a larger surface area, protecting the assembly material from damage and preventing the bolt from loosening due to vibration—a critical requirement in automotive applications. NAS523 is a standardized Fastener Code system established
The defining feature of the NAS523 is its head geometry. Unlike a standard 12-point or hex head bolt, the NAS523 head is designed to minimize the "wrenching diagonal"—the distance measured across the corners of the head. Relevance score = 0