Fortis LE Lightweight Enhanced End Plate with K1 System Castle Nut

Fortis LE Lightweight Enhanced End Plate with K1 System Castle Nut

Product Code:
Calculated at Checkout
$44.95 $42.70



  • Tapered castle nut to seat and seal itself into place without the need of staking the end plate
  • No ratcheting, no set screws, no backing out and no failures
  • Quick Detach Socket - 360º rotational locking interface
  • Available in anodized black, blue, flat dark earth, gold, grey, and red finish


  • Material: 7075-T6 Aluminum
  • Finish: Anodized Black, Blue, Flat Dark Earth, Gold, Grey, or Red
  • Weight:
    • Endplate: 0.42 oz.
    • Castle Nut: 0.14 oz.


  • AR-15 and AR-10

**Anodized areas that touch between the end plate and castle nut will have expected minor scratches from torquing of the castle nut.

**Due to various factors that take place during the anodization process, the color lines from batch to batch of a certain product may vary.


  • 1x Fortis Lightweight Enhanced K1 End Plate
  • 1x Fortis K1 Tapered Castle Nut


How many times have you went to remove the castle nut on your AR, slipped and scuffed it? I know, if it's staked properly, it can be hard to break loose and things happen. It's just a little thing, you can barely see it, but you know it's there. When you change to a Fortis K1 Castle nut locking system you will never have to mess with staking that thing again.

There Is Another Way to Skin A Cat

The revolutionary design of the Fortis tapered castle nut is made to work with the Fortis LE End Plate. Together they securely attach your buffer tube without having to stake anything in place. The outer circumference of the tapered castle nut wedges itself into the tapered inner surface of the Fortis LE End Plate to create a perfect bond that virtually guarantees it won't back off. Of course, you are still going to want to use an armorers wrench to torque down the Fortis K1 Castle nut, but it will stay tight without having to stake it in place.

One Less Step When Installing the Fortis K1 Castle Nut

Properly staking a castle nut isn't really that big of a deal, but sometimes breaking it loose can be. I worked on a friend's AR once, he had used Locktite on the castle nut on top of staking it. It took heat and some bad words to get it loose. Well, the Fortis LE End Plate combined with the fitted, tapered castle nut locks in tight and comes off easily, heat and bad words are not requried. Additionally, Fortis machined an attachment point for a QD sling swivel into the enhanced endplate. This cutting-edge convenience should be on your gun today.

Write a Review

9 Reviews

  • Not worth your money!

    Posted by Christopher Jurkowski on 23rd Feb 2021

    I received the castle nut and end plate and it looked very promising. The moment I touched it with an armorer's wrench, the finish started coming off. The castle nut looks like hot garbage now and I am unable to replace just the nut because you have to buy the full assembly. Do yourself a favor and don't waste your money on this. For over $40, it's not worth it. I emailed Fortis a couple times. No response. I am very dissapointed. You shouldn't pay good money for junk. Many better options out there. Fortis doesn't stand behind their products.

  • Fortis Quality

    Posted by William Ferrel on 18th Feb 2021

    I have purchased a few fortis parts for my builds. The quality is consistently high. Never machining Mark's or bad anodizing. Tolerances are consistent and uniform. This castle nut and end plate is no exception. The tapered end plate helps lock the castlenut in nicely without having to over torque. Just take it slow and steady on install then one last good steady pressure and its locked in. I've had no issues and would reccomend this product.

  • Best castle nut system

    Posted by Johnny on 18th Feb 2021

    After investigating and physically comparing other brands, I saw the Fortis system as the most promising, best quality, light, and best looking. I had mine cerakoted to eliminate any scratching issues. The system locks in beautifully and holds the buffer tube with no issues.

  • Fortis End Plate

    Posted by Robert Cessna on 10th Apr 2020

    Great end plate and castle nut system. Everything Fortis is high quality first of all. But this product not only looks cool, it is easy to disassemble and tighten. Have this one several of my builds now and plan to make it standard when needed.

  • Good quality

    Posted by Kyle on 3rd Apr 2020

    It looks good, light weight, holds solid so far. The threads were a little gritty at first so be careful not to cross-thread during install.

  • Huge improvement over milspec!

    Posted by Steve'o on 6th Feb 2020

    Always assumed castle nuts and end plates couldnt offer me much. Was I wrong... I've tried Strike Industries enhanced kit and this is much lighter, smaller, and sexier in my opinion. The lock up when torqued down feels solid as a rock. You get full range of motion on your buffer tube unlike the SI design. If I'm not mistaken, its less costly as well. No brainer for future builds!

  • Fortis LE K1 Castle Nut

    Posted by Jeff on 22nd Dec 2019

    Installation is easy, it's just an end plate and castle nut. The torque I needed to secure my buffer tube from movement was more than the advertised 1/8 or 1/4 turn, it was closer to 1/2 turn. Even after that, there weren't any markings in the finish from my wrench on the nut, so good job Fortis.
    I haven't tested the QD mount yet. I've had a failure with a QD in the past, and on this build I was planning on going with a snap hook, but this castle nut looked so cool I accepted the QD mount. So I can't review that part of it.
    The finish is extra glossy and very black, which probably would look better on a Fortis brand built rifle. On mine it stands out a bit being more rich in gloss and color, but it still looks good. It just makes the receiver look bad. It matches the sheen of my BAD magazine release.

  • Very Light But Not Well Thought Out

    Posted by Jake on 31st Oct 2018

    I purchased the gold version of this, mainly because the black was sold out, and I can image that the black will have the same issue. Upon torquing the castle nut down, I noticed that the gold anodizing started to rub off. This is due to the friction/taper lock design. The anodizing does not hold up to friction. Now I have a gold/raw aluminum castle nut. This could have been prevented had the end plate not been machined in a wavy pattern. If the they would have omitted the machining of the wavy spot it would cover up the areas on the castle nut were the anodizing rubbed off of the taper.

    I would not recommend this to anyone and would say wait for the K2 version.

  • Cutting edge

    Posted by Justin on 16th Oct 2018

    What a brilliant way to deal with the ole castle nut / end plate situation. It is a well built, precision part that is shockingly light, fully functional and the only setup I will buy from now on.... Awesome!!

[ ]