Strike Industries Enhanced Castle Nut and Extended QD End Plate

Strike Industries Enhanced Castle Nut and Extended QD End Plate

Product Code:
Calculated at Checkout
$57.95 - $59.95



  • Centrally placed quick detachable (QD) socket for right or left hand sling use
  • Aesthetic upgrade
  • Easy drop in installation
  • Available in Black, Flat Dark Earth, Blue, and Red finish!


  • Material:
    • Enhanced Castle Nut: Steel
    • Extended QD End Plate: 6061-T6 aluminum
  • Finish: Hard anodized
  • Weight:
    • Enhanced Castle Nut: 0.95 oz.
    • Extended QD End Plate: 0.95 oz.


  • Carbine buffer tube

*First position on buffer tube will be lost due to the extended length of the Enhanced Castle Nut. Due to dimensional tolerances between some manufacturer's receiver extension collar lengths and differing amount of true threads on various buffer tubes, some may experience difficulties installing. Please contact for a replacement castle nut if you cannot install.

*Recommended torque value 40 inch pounds.


  • 1x Strike Industries Enhanced Castle Nut
  • 1x Strike Industries Extended QD End Plate


Strike Industries has made a name for itself addressing needs that are frequently overlooked by the rest of the firearms industry. With a reputation for attention to detail, you can bet that when Strike offers a parts kit, it’s something special. Strike Industries’ Enhanced Castle Nut and Extended End Plate kit is no exception. When you install these pieces on your rifle you’ll wonder why someone didn’t do it this way sooner.

When you order a Strike Industries Enhanced Castle Nut (ECN) and Extended End Plate (EEP) kit you’ll receive an Extended QD End Plate and an Enhanced Castle Nut.

The Strike Industries EEP includes a Quick Detach Sling Swivel Mount in the center where it functions ambidextrously. The mount has been repositioned from the traditional placement, eliminating the risk of painful pinches to the webbing of the operator’s primary hand. You’ll handle your weapon more confidently, even in close quarters, because you don’t have to worry about painful accidents due to poor ergonomics.

Strike designed the ECN to better support the threaded part of your receiver’s extension and match the length of the Extended End Plate. The result is a better looking, more secure and functional ECN/EEP kit that you’ll be happy to have on your rifle whether you’re out on maneuvers or at the range.

Strike’s team of engineers and craftsmen has done it again with the Enhanced Castle Nut and Extended QD End Plate. They’ve made simple changes to small parts that others overlooked and improved the operator’s experience in the real world.

Note: Receiver Extension Tube (RET) may become damaged if EEP is installed on RET and then forced far enough rearward to allow full threading onto Billet or polymer lower receivers that have a RET support flange with a depth greater than 0.503."


Receiver Extension Tube support flange

Write a Review

28 Reviews

  • FDE Enhanced Castle Nut

    Posted by Cedric on 4th Jun 2021

    This item adds a unique look to the firearm, quick disconnect is conveniently placed, install was easy, plan to purchase for future builds.

  • Enhanced castle nut

    Posted by Eugene Anderson on 14th Apr 2021

    Really nice gives a great stylish look.

  • Enhanced castle nut

    Posted by Eugene Anderson on 11th Apr 2021

    Very nice quality and looks are flawless.

  • SI does it again

    Posted by Randy L Stanton on 25th Mar 2021

    This is the second ECN/EEP I've gotten. One red and one blue for different rifles. Easy install if you have the right tools and take your time. Torque wrench is a must. I've seen some reviews about varying colors. If you mix and match from different manufacturers you can almost guarantee a color variance due to the anodizing differences between makers although their red matches many others their blue is lighter than most. SI colors have been a spot on match for every part I've gotten from them in both red and blue (trigger guards, charging handles, pivot/takedown pins, ECN/EEP, selector switches, angled QD mounts).

  • Excellent Product, Poor coloration

    Posted by Combat Tuna on 24th Nov 2020

    I purchased this endplate/castle nut combo for a custom match rifle build, and the aesthetics are awesome for it. Just different enough to stand out, but not obnoxious or overdone. Super easy install and lightweight are a plus. My only issue is with the color; While the picture online shows a bright, deep blue color that I was expecting to match nicely with the other bright blue anodized parts on my rifle, the actual part has an almost "frosty" matte finish, causing it to look almost purple in color. If I had to order it over again I would have gone with the black one instead, as the difference in texture and color saturation is pretty extreme compared to my other parts and the product picture.

  • Great product..

    Posted by John H on 30th Oct 2020

    Very good item from a very good company. I like the new Tribus version even better! A high price but great functionality and looks!


    Posted by MYKOLA on 12th Aug 2020

    Good quality and looks very good.Combines very well with tube and covers threads.

  • Great Product

    Posted by Tua415 on 6th Aug 2020

    Fast shipping, well packaged, and a great product. Fits perfect. Thank you.

  • Buy it!!!

    Posted by Dan on 7th May 2020

    Wish I would have bought this with the rest of parts first. Aero precision castle nut that came with my buffer kit tube actually cracked after firing first so I got this to replace it and couldn’t be happier. Looks great and protects tube threads.

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