Fortis Manufacturing

Overview

The Fortis Castle Nut is a standard type castle nut finished in a hardcoat anodized black, providing durability and a sleek appearance for your AR-15 build. This component securely fastens the buffer tube to the lower receiver, ensuring proper alignment and function of the recoil system. It’s commonly found in builds that feature a mid-length gas system chambered in 5.56 NATO, making it a reliable choice for those configurations.