: Remember that for countersunk (flush) rivets, the length includes the head. For universal (protruding) head rivets, the length is measured from the bottom of the head to the end of the shank. Your reference PDF should clearly illustrate these measurement boundaries.
: Represents an MS20470AD universal-head rivet manufactured from 2117-T3 aluminum alloy (commonly referred to as an "AD" rivet).
By reading this four-sided anchor point, an aircraft technician immediately knows the fastener type, composition, installation orientation, material preparation steps, and sizing. Detailed Breakdown of the Four Quadrants nas523 pdf top
A correctly driven rivet should have a "shop head" height of 0.5 x Diameter and a width of 1.5 x Diameter
NAS standards are documents that establish uniform engineering and technical requirements for items, materials, processes, and services for use in aerospace and industries. The standards cover a wide range of topics, including fasteners, electronic components, and more. : Remember that for countersunk (flush) rivets, the
It looks like a cross (+) with information in the four quadrants.
: The core standard of the rivet (e.g., MS20470, NAS1097, BACR15CE). The standards cover a wide range of topics,
Specifies the rivet part number (e.g., AN or MS prefix) and its material alloy. For example, the code "BJ" might identify an MS20470AD rivet made of 2117 aluminum alloy.
: Outlines special hole preparation requirements, such as dimpling ("D") or countersinking ("C"). Complex codes like "D2C" instruct the technician to dimple the top two sheets and countersink the third.
: Fastener diameters are universally written as numbers representing 1/32-inch increments . A value of 3 denotes a 3/32-inch diameter; a 4 signifies a 1/8-inch (4/32) diameter; and a 5 denotes a 5/32-inch diameter.
Do not trust a blurry, watermarked, free PDF from an unknown forum. The cost of a counterfeit fastener lot entering your assembly line due to a misread NAS523 table is millions of dollars in liability. Invest in the document. Train your team on the top procedures. And keep that PDF—whether digital in your QMS or printed in your inspection lab—updated to the latest revision.