Faxon® Receiver Lock Nut / Castle Nut AR-15 Castle Nut
Secure Receiver Extension Lock-Up for AR-15 Platforms
The Faxon® AR-15 Castle Nut is a precision-machined component designed to secure the receiver extension (buffer tube) to the lower receiver. Built for reliability and consistent fitment, it provides a solid interface for maintaining proper alignment of your AR-15 stock assembly.
Durable Steel Construction
Manufactured from steel, this castle nut is engineered for long-term durability under repeated installation and hard-use conditions. Its robust construction ensures dependable retention when properly installed and staked.
Mil-Spec Compatible Fitment
Designed to interface with mil-spec AR-15 receiver extensions, the Faxon castle nut supports compatibility with standard buffer tube assemblies and lower receivers. It integrates seamlessly into both factory builds and custom configurations.
Essential Component for AR-15 Builds
Whether assembling a new rifle or replacing worn hardware, the Faxon® AR-15 Castle Nut provides a reliable solution for securing your buffer system. Proper installation and staking help ensure consistent performance and long-term stability.
Faxon® AR-15 Castle Nut Specifications
- Platform Compatibility: AR-15
- Interface: Receiver Extension / Buffer Tube
- Compatibility: Mil-Spec AR-15 Components
- Made In: U.S.A.
Reliable Retention for Buffer Tube Assemblies
The Faxon® AR-15 Castle Nut is a simple but critical component that ensures your receiver extension remains properly secured. Built to Faxon’s standards for fit and durability, it’s a dependable choice for both new builds and maintenance replacements.
Compatibility Notice: Designed for AR-15 platforms using mil-spec receiver extensions. Always ensure proper torque and staking during installation for optimal retention.
Product Information
| Manufacturer | Faxon |
|---|---|
| Platform | AR10 (DPMS), AR15, AR9 |
| Color | Black |
| Finish | Phosphate |
| Compatibility | Standard AR15 components, Standard DPMS AR10 Components |
| Weight | <1oz |
| Made in USA | Yes |















