The Fortis Standard Castle Nut is a billet aluminum replacement for the stamped steel castle nut on an AR-platform buffer tube (Fortis part no. CN-Stand). It is machined from a solid piece of aircraft-grade aluminum, cutting meaningful weight versus a stock steel castle nut without sacrificing durability. It threads onto any mil-spec buffer tube the same way the factory part does, so it is a simple, direct way to shave ounces and upgrade the look of a lower build.

Key Specifications

• It is machined from solid billet aircraft-grade aluminum rather than stamped steel.
• It offers a significant weight reduction compared to a factory steel castle nut.
• It fits any mil-spec buffer tube, threading on the same way the stock part does.
• A castle nut like this retains the receiver end plate against the buffer tube, keeping the stock assembly from loosening under recoil.

Frequently Asked Questions

Will this fit a mil-spec buffer tube? Yes, it is built to thread onto any standard mil-spec AR-platform buffer tube.

Why choose an aluminum castle nut over the factory steel part? The billet aluminum construction cuts meaningful weight versus a stamped steel castle nut while keeping the same fit and function.

Buy the Fortis Standard Castle Nut, Billet Aluminum

Order it directly from our Lubbock, Texas gun shop for fast, insured shipping to your door. Shop the full Fortis Manufacturing lineup and browse our AR buffer system selection for more build components.