Free Shipping & Free Returns*

FREE SHIPPING on Over 250,000 Products

Enjoy free shipping during the holidays! Shop now and get Free Value Shipping on most orders over $49 to the contiguous 48 states, DC and to all U.S. Military APO/FPO/DPO addresses.

Enjoy Our Extended FREE RETURNS

We want to ensure that making a return is as easy as possible! With our Hassle-Free, Extended Holiday Returns, eligible orders placed from November 12, 2025 on will benefit from an extended return deadline (January 13, 2026 or 30 days after receipt of your order - whichever is later). We'll even cover the cost of return shipping. Learn more about our Return Policy.

Shopping Cart
Fortis Manufacturing AR-15 LE Tapered Castle Nut/End Plate K1 System
As Low As $34.63 Save Up to 38%
View Product
Compare (0)
Most Helpful Positive Review BEATS MILSPEC
I've always just ran mil spec castle nuts and end plates and figured I'd try something different. Glad that I did. The quality of the machining is excellent and it gives a nice solid lockup for a QD sling. Couldn't be easier to install. Not that milspec ones are hard but these can pretty much be don...
Read More...
Most Helpful Negative Review Great idea; poor execution
I've installed 2 of these now, and neither worked as advertised. The first was on an AeroPrecision receiver extension; the second was on a Spike's. . The product description and manufacturer videos do not state any need for special installation tools. However, in using both a generic armorer's t...
Read More...
Show
Sort by
Filter by

great addition

by william, Verified Owner from TX, United States Written on April 26, 2025
Lightweight. Durable. Looks good and allows for easy detachable sling.
Would recommend: Yes
Was it helpful to you? Yes | No

looks good but kind of expensive

by spund gun, Verified Owner from CO, United States Written on April 25, 2025
The castle nut is really cool and just what I needed for my build. If you need a standard castle nut you can get one much cheaper. But if you are looking for a more non-tactical custom build look this is spot on.
Pros:
  • the cool look
Cons:
  • cost
Best Used for:
  • Custom Builds
  • non tactical
Would recommend: Yes
Was it helpful to you? Yes | No

Billy castle nut review

by Billy III, Verified Owner from FL, United States Written on February 17, 2025
This is a simple piece of your stock but it gives you like 2 castle nuts for extra security , you can match the color to your custom stock or just use this castle nut on your current build, it has this click sound and tactile feel so you nos for sure everything is good to go…..I highly recommend this product if you want a quality and extra safe feeling your stock is properly attached.
Pros:
  • Build quality
  • competitive price
  • Custom Color
Cons:
  • At this time do not have any cons
Best Used for:
  • Stock attachment
  • Rear Stock attachment
Would recommend: Yes
Was it helpful to you? Yes | No

Nice product, but not worth the price

by GunPlumber, Verified Owner from NV, United States Written on February 1, 2025
Nice product, but not worth the price, feels so cheap made out of aluminum, if your looking to save weight, then this is probably right for you. I'm more into this product to see how long it takes for the Castle nut to start moving, even though product guarantees it is locked when installed correctly, now only time will tell.
Pros:
  • its Light weight
Cons:
  • color
  • price,
  • soft metal that is easy to bugger up the notches
Best Used for:
  • Any AR application
Would recommend: No
Was it helpful to you? Yes | No

Good fit and finish

by Johnny Ultra, Verified Owner from FL, United States Written on January 17, 2025
Fit and finish. Fits and looks good. No issues, it just fits right.
Pros:
  • Good aestheticly
Cons:
  • None
  • None especially at price point
Would recommend: Yes
Was it helpful to you? Yes | No

Serves its purpose.

by Rufus Speed, Verified Owner from AR, United States Written on January 11, 2025
Seems to be very well constructed and adds a touch of uniqueness.
Would recommend: Yes
Was it helpful to you? Yes | No

Great product

by Peter Piper, Verified Owner from CA, United States Written on January 7, 2025
Fortis makes great stuff. Honestly i doubt anyone needs a product review for it, but looks great and instals as it should
Would recommend: Yes
Was it helpful to you? Yes | No

Fortis AR-15 LE Tapered Castle Nut/End Plate

by Gk, Verified Owner from UT, United States Written on December 26, 2024
I love this castle nut/end plate system .... No Staking Necessary..
Would recommend: Yes
Was it helpful to you? Yes | No

great upgrade

by neb grendel, Verified Owner from NE, United States Written on December 23, 2024
Ive used 2 of these before and they work great. Ive never had one come loose. Looks great and adds some nice features without having to stake a castle nut
Pros:
  • features
  • Looks
  • No staking
Cons:
  • None
Best Used for:
  • Any build
Would recommend: Yes
Was it helpful to you? Yes | No

AR QD Buffer plate

by Harpdog, Verified Owner from SC, United States Written on November 1, 2024
Good fit and quick attached on AR buffer and has its own castle nut
Pros:
  • None
Cons:
  • none I experienced
Best Used for:
  • AR Lower receiver application
Would recommend: Yes
Was it helpful to you? Yes | No
There are no reviews that match your criteria. Would you like to review this product?