The MS20426AD4-8 is a 100° countersunk (flush head) solid aircraft rivet made from 2117-T4 aluminum alloy (AD series), designed for structural sheet metal assembly where a smooth aerodynamic surface is required.

The “4” indicates a 1/8" diameter, and the “-8” dash number corresponds to a 1/2" length, making it suitable for thin aircraft skin and light structural stacks where a flush finish is necessary after installation. It is part of the standard MS20426 / AN426 rivet family used throughout certified aircraft structures.

This rivet is installed using a pneumatic rivet gun and bucking bar, with the head seated in a 100° countersunk hole. The shank is then deformed on the opposite side to form a shop head, creating a permanent structural joint used in aircraft skins, fairings, and aerodynamic panels.

The 2117-T4 (AD) alloy provides good shear strength, corrosion resistance, and self-aging properties after installation, making it a standard material in aviation sheet metal work.

Key features include:

MS20426 100° flush head solid aircraft rivet
Size: 1/8" diameter × 1/2" length (-8 dash number)
Material: 2117-T4 aluminum alloy (AD series)
Approx. ~1500 rivets per 1 lb pack
Flush (countersunk) head for aerodynamic surfaces
Requires 100° countersunk hole preparation
Installed with rivet gun + bucking bar
High shear strength (~26,000 PSI typical)
Heat-treated self-aging aluminum alloy
Corrosion-resistant surface treatment (MIL-spec anodize/chromate)
Common in aircraft skins, fairings, and exterior structures
Standard replacement for AN426AD4-8 in aircraft maintenance
Used where smooth airflow and flush surface finish are required