LBE Unlimited Castle Nut for AR-15 – Manganese Phosphate (ARCNUT)

• Castle nut designed for securing buffer tube to AR-15 lower receiver
• Constructed from 4140 steel for strength under torque and repeated use
• Manganese phosphate finish provides corrosion resistance and surface durability
• Compatible with AR-15 receiver extension assemblies and buffer tube systems
• Used during rifle assembly to retain end plate and buffer tube components
• Made in the USA ensuring consistent manufacturing and material quality standards

The LBE Unlimited AR-15 Castle Nut is a castle nut designed for securing the receiver extension to the lower receiver in AR-15 rifles. The LBE Unlimited AR-15 Castle Nut provides the threaded locking interface required for buffer tube installation.

This castle nut is constructed from 4140 steel and features a manganese phosphate finish. It is made in the USA and fits AR-15 platforms. The LBE Unlimited AR-15 Castle Nut is categorized under small parts and builder hardware and installs onto the receiver extension threads. This product is used for locking the buffer tube in place during assembly. In standard configurations, it interfaces with the end plate and lower receiver. The steel construction provides consistent thread engagement and retention. In typical setups, it is used during builds or replacement of worn components.