AT3™ Castle Nut for AR-15 Buffer Tubes – 9 Colors Available

Out of Stock
Orders will Ship within 1 Business Day
Backed by the AT3 Lifetime Warranty!
TOP ADD-ON'S
AT3 Tactical FU-BAG Lost Parts Kit - Because Oops Happens

AT3™ FU-BAG™ AR-15 Lost Parts Kit – Springs, Detents, Replacement Components

$7.99
AT3 Tactical Spear M-LOK Free Float Handguard 9 Inch with Slick Side Billet Upper Receiver

AT3™ Upper Receiver and SPEAR Handguard Combo - Black, 9 inch

$169.99

Secure Your AR15 Buffer Assembly with a Steel Castle Nut

This steel castle nut is an essential piece of an AR15 buffer tube/stock assembly.  With standard cuts for use with armorer’s wrench, and smaller cuts for “staking” the castle nut and endplate for a secure hold, this part does everything it should at a good price.  If you’re in need of a spare for a new build or replacing a damaged component, this one is right for you.  You can also add a little more color to your black rifle with with your choice of Cerakote™ finish. You can choose from FDE, ODG, Pink, Blue, Red, Burnt Bronze, Tungsten, and Titanium.

Specifications

  • Material: Steel
  • Finish
    • Black: Phosphate
    • Flat Dark Earth: H-267 Magpul® Flat Dark Earth
    • OD Green: H-232 Magpul® OD Green
    • Pink: H-224 SIG™ Pink
    • Red: H-167 USMC Red
    • Blue: H-171 NRA Blue
    • Burnt Bronze: H-148 Burnt Bronze
    • Tungsten: H-237 Tungsten
    • Titanium: H-170 Titanium
  • Thread: Mil-Spec
  • Compatible with armorer’s wrench

Products available on this page:

Have Questions About this Product?

The AT3 Tactical store has a 90 day no-hassle return policy for products in good condition. You can view the full details of our return policy here.

If you encounter an issue or defect with a product after 90 days of your purchase, you can refer to the manufacturer for a warranty claim. Their policies are below.

AT3 Lifetime Warranty Logo

All AT3 Tactical Brand Products carry a lifetime warranty against manufacturer’s defects.

This includes AT3 Red Dot SightsHandguardsIron Sights, and any other product that carries the “AT3 Tactical” or “AT3™” name. For other brands (ex. Magpul or Troy), please refer to the manufacturer’s warranty policy.

In the event that your AT3™ product becomes unusable, we will repair or replace the product at no charge to you.

If we cannot repair your product, we will replace it with a product in perfect working order of equal or better physical condition. The warranty is fully transferable, but we may require information about the original purchase to validate the authenticity of the product.

If your product is in need of warranty service, please contact AT3 Tactical to start the process

Our contact info is available here. To expedite processing, please provide your order information and description of the defect.

Please note: The AT3 Lifetime Warranty does not cover loss, theft, intentional damage or cosmetic damage that doesn’t affect the performance of the product.

Customer Reviews

Based on 93 reviews
96%
(89)
1%
(1)
1%
(1)
1%
(1)
1%
(1)
E
Eliseo Melendez
Castle Nut

Looks great, it was exactly what I was looking for. Thank you.

Thanks for sharing your feedback! We're glad you're satisfied with your purchase.

D
Darryl M
AT3 Castle nut in Burnt Bronze

This nut not only secures my QD end plate, but it looks FLY on my BB 223 Wylde build!

Thanks for sharing your feedback! We're glad you're satisfied with your purchase.

R
Roy E Hooker
Awesome FDE finish

Perfect FDE to my orther FDE and Magpul, Aero FDE, definitely a premium part for awesome price, AT3 is not messing around. Will buy from them again . Don’t forget fast shipping. 3 days after shipped. That’s fast shipping Hooah!!

Thanks for sharing your feedback! We're glad you're satisfied with your purchase.

M
MarQ Patriot
Solid...

I was purchasing parts to finish a lower(have not started it yet)and future build. Castle nuts are castle nuts, right? Not really, I did purchase this for the price and cause it was in stock(lol)but I must say it is very good quality even at $4.... No burs on the edges, wrench cuts and punch grooves are precise and clean. It seams to be a solid part and I’m sure it will do the job... Thank you, AT3...

Thanks for sharing your feedback! We're glad you're satisfied with your purchase. Cheers!

D
Dave Renfroe
Castle Nut

Just a plan castle nut at a normal price but with all these want to be people trying to build AR's because of covad you cant find anything local. AT3 is always my place to go when I cant find it local and they are the place I go because they beat most local prices on high end parts. Shipping is just sick, Parts are always on time if not earlier. AT3 Rocks!!!!!

Customers who viewed this item also viewed these products

AT3™ Mil-Spec AR-15 Safety Selector - 9 Colors Available

$8.49
Mil-Spec AR-15 Safety Selector The classic mil-spec safety selector is a great choice for
AT3™ AR-15 M-LOK Handstop - Black

AT3™ AR-15 M-LOK Handstop - Available in 9 Colors

$19.99
A Small Addition To Your AR For A More Positive Handling & Improved Weapon
AT3™ Mil Spec Buffer Tube Kit For AR-15

AT3™ Mil Spec Buffer Tube Kit For AR-15 - 9...

$39.99
The perfect kit for your next build – at a price that can’t be
Choose from 7 Colors

AT3™ Ambidextrous AR15 Safety Selector - 9 Colors Available

$24.99
A Quick Upgrade to Any AR-style Rifle The AT3 AR-15 Ambidextrous Safety Selector replaces
Fortis Standard AR-15 Castle Nut - AT3 Tactical

Fortis Standard AR-15 Castle Nut

$16.95
Lightweight Aluminum Castle Nut Only a third of the weight of a mil-spec steel
AT3™ Mil-Spec AR-15 Pivot Pin - 7 Colors Available

AT3™ Mil-Spec AR-15 Pivot Pin - 9 Colors Available

$2.99
Mil-Spec AR-15 Pivot Pin This heavy-duty Mil-Spec Pivot Pin securely locks into and holds

Strike Industries Enhanced AR-15 Castle Nut with Extended QD Endplate

$57.95
Elevate Your AR-15 with Strike Industries’ Enhanced Castle Nut and End Plate The Strike

AT3™ Mil Spec AR-15 Buffer Tube - 9 Colors Available

$17.99
Mil-Spec AR-15 Carbine Buffer Tube Made 6061-T6 aluminum construction with a black anodized finish,
LBE Unlimited AR-15 Castle Nut

LBE Unlimited AR-15 Castle Nut

$8.49
LBE Unlimited AR-15 Castle Nut The LBE Unlimited AR15 Castle Nut is an essential

AT3™ Mil-Spec AR-15 Magazine Catch Button - 9 Colors Available

$2.99
Mil-Spec AR-15 Magazine Catch Button All AT3 Tactical lower receiver parts meet or exceed

AT3™ Mil-Spec AR-15 Magazine Catch - 9 Colors Available

$6.49
Mil-Spec AR-15 Magazine Catch This magazine catch meets and exceeds mil-spec demands.  Steel construction

AT3™ Mil Spec End Plate for AR-15 - 9 Colors...

$2.99
Mil-Spec Steel Endplate for AR15 Lower Receivers This standard endplate is compatible with any

Frequently purchased together

AT3 Tactical AR-15 Magazine Catch and Button Assembly

$9.99
AR-15 Magazine Catch with Button and Spring Whether you’re finishing a build or replacing
UTG Pro Mil-Spec Buffer Tube 6-Position Receiver Extension

UTG Pro Mil-Spec AR 15 Buffer Tube 6-Position Receiver Extension

Superior Quality Mil-Spec Buffer Tube – Unbeatable Value The UTG Pro 6-position Mil-Spec receiver

Timber Creek Outdoors Mil-Spec AR 15 Buffer Tube

$31.99
7075 Aluminum Buffer Tubes Finished in Durable Cerakote Timber Creek Outdoors shows us once
Choose from 7 Colors

AT3™ Ambidextrous AR15 Safety Selector - 9 Colors Available

$24.99
A Quick Upgrade to Any AR-style Rifle The AT3 AR-15 Ambidextrous Safety Selector replaces

AT3™ FU-BAG™ AR-15 Lost Parts Kit - Springs, Detents, Replacement...

$7.99
Made an “Oops” with your New Build?  You Detent-Launchin’, Spring-Losin’ Fool, you. We’ve all

AT3 Tactical Standard GI AR 15 Charging Handle - 9...

$18.99
Classic Mil-Spec Charging Handle – Light and Strong – A Great Value Easily chamber

AT3™ Pro-Builder™ AR-15 Lower Parts Kit - No Grip or...

$29.99
Perfect Lower Parts Kit for the Premium Builds This quality lower parts kit excludes
AT3 Tactical Carbine Buffer Spring for AR15

AT3™ Carbine Buffer Spring for AR-15

$6.99
Carbine Buffer Spring for 6-Position Adjustable Buffer Tubes This spring will fit in any
AT3 Tactical Carbine Buffer Weight for AR15

AT3™ Tactical H2 Buffer (4.6 oz) for AR-15

$18.99
The Best Fix for an Overgassed AR – H2 Carbine Buffer Weight This one-piece

AT3 Tactical AR-15 Bolt Catch Assembly with Spring, Plunger, and...

$7.99
Mil-Spec AR-15 Bolt Catch with Hardware The AT3 AR-15 Bolt Catch Assembly has everything

AT3 Tactical AR-15 Takedown and Pivot Pin Assembly

$8.99
AR-15 Takedown and Pivot Pins with Springs and Detents If you’re completing an AR-15
AT3 Tactical Castle Nut for AR15

AT3™ Castle Nut for AR-15 Buffer Tubes - 9 Colors...

$3.99
Secure Your AR15 Buffer Assembly with a Steel Castle Nut This steel castle nut