Can I reuse an AR-15 castle nut?

If the threads and notches are undamaged, yes. Many builders prefer to replace castle nuts when performing maintenance or upgrades for added reliability.

Do all AR-15 castle nuts require staking?

Mil-spec castle nuts typically require staking to prevent loosening under recoil. Enhanced and anti-rotation styles may not need staking depending on their design.

Are these castle nuts compatible with any AR-15 buffer tube?

Yes, all our mil-spec size castle nuts fit standard AR-15 carbine buffer tubes. Always check specifications if using non-standard components.

Do you sell AR-15 buffer tube kits with castle nuts included?

Yes, we offer complete AR-15 buffer tube kits that include castle nuts, buffer tubes, recoil springs, and end plates. Visit our AR-15 buffer tube kit page for options.

AR-15 Castle Nut | Mil-Spec, Enhanced & Anti-Rotation Nuts

**Timber Creek Outdoors AR Castle Nut** $6.99

**Luth-AR Carbine Lock Ring/castle Nut** $4.75

**Strike Industries AR Enhanced Castle Nut & Extended End Plate** $57.95

AR-15 Castle Nuts for Reliable Buffer Tube Lockup

When assembling an AR-15, securing the buffer tube with a solid lock nut is essential. Castle nuts keep the buffer tube firmly attached to your lower receiver, helping maintain stability and consistent performance.

At Mounts Plus, we stock mil-spec, enhanced, and anti-rotation options—all designed to meet the needs of AR builders and firearm enthusiasts.

Why a Quality Castle Nut Matters

Castle nuts play a simple but critical role: they hold your buffer tube and end plate in place. A properly installed nut keeps your stock or brace secure and helps prevent unwanted movement over time.

Benefits include:

Reliable buffer tube alignment
Improved durability under recoil
A cleaner, more secure rifle build

Castle Nut Options We Carry

Mil-Spec Castle Nuts

Standard size
Steel construction
Suitable for most AR-15 carbines

Enhanced Castle Nuts

Lightweight aluminum or coated steel
Designed for custom or minimalist builds

Anti-Rotation Castle Nuts

Extra security for tactical rifles
Works with anti-rotation end plates

Choosing the Right Nut for Your Rifle

Nut Type	Best For	Key Feature
Mil-Spec	Standard AR builds	Stakeable steel
Enhanced	Lightweight builds	Slim profile
Anti-Rotation	Duty and defense rifles	Lock tab design

Installation Basics

Slide the end plate over the buffer tube.
Thread the nut on by hand.
Tighten with an armorer’s wrench to about 40 ft-lbs.
Stake it, if needed, to secure everything in place.

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Looking to complete your AR-15 build? Check out these related parts and accessories:

Pair your castle nut with a complete AR-15 Buffer Tube Kit for a full installation setup.
Need a new buffer tube? Browse our selection of AR-15 Buffer Tubes including mil-spec, commercial, and pistol options.
Upgrade your rifle with a durable AR-15 End Plate compatible with anti-rotation features.
Don’t forget AR-15 Lower Parts Kits to finish your lower receiver build.
Explore more AR-15 Accessories to customize your rifle setup.

Frequently Asked Questions (FAQ)

Q: Can I reuse a castle nut?
A: If it’s undamaged and holds torque, yes. Many builders prefer using new parts for peace of mind.

Q: Do I need to stake my castle nut?
A: Staking is recommended for most standard builds, especially with mil-spec parts.

Q: Will your castle nuts fit any AR-15 carbine buffer tube?
A: Yes, our products match standard AR-15 specs.

Q: Do you offer complete AR-15 kits with these nuts?
A: We do. See our AR-15 buffer tube kits.

Final Note

At Mounts Plus, we offer castle nuts that match both performance and budget needs. Whether you prefer mil-spec reliability or enhanced designs, you’ll find trusted parts and fast shipping here.