Strike Industries Multi-Function End Plate and Anti-Rotation Castle Nut

Strike Industries Multi-Function End Plate and Anti-Rotation Castle Nut

Product Code:
Calculated at Checkout
$28.95 $26.95



  • Set screw to retain takedown pin and detent for ease of installation
  • No peening or staking needed with the Anti-Rotation Castle Nut/End Plate design
  • Anti-rotate QD socket
  • Multiple sling attachment points


  • Material: Steel
  • Finish: Black
  • Weight:
    • Multi-Function Endplate: 0.71 oz.
    • Anti-Rotation Castle Nut: 0.63 oz.


  • AR-15 and AR-10


  • 1x Multi-Function Endplate
  • 1x Anti-Rotation Castle Nut
  • 1x Detent Set Screw
  • 1x Anti-Rotation Set Screw





How many times have you heard this: “Well, that’s the way we’ve always done it.”? It doesn’t matter where it is, that’s dangerous talk. When you’re talking about a subject as dynamic and progressive as tactical firearms, it’s downright restrictive, antique thinking. Something as seemingly simple as the traditional installation and peening of the AR 15 castle nut bogs down progress. In order to free the armorer who wants to rebuild rifles, or swap out parts as better choices come to market, Strike Industries has developed the SI Anti-Rotation Castle Nut (ACN) and Multi-Function End Plate (MFEP.)

A Simple Idea Opens Doors for You

Strike Industries was built on supplying the small arms community with superior versions of products that other manufacturers don’t bother with. Their Anti-Rotation AR 15 Castle Nut and Multi-Function AR End Plate Set features a detent set screw and anti-rotation set screw to secure your system rather than using the old way of securing the receiver extension by peening or staking. The result is added flexibility you might never have thought about before but will enjoy when it comes time to replace worn parts or try something new. You’ll no longer hesitate to do something just because it’s a pain in the neck to disassemble.

Be Flexible, Stay Ahead

You want every edge you can get. Now, you can easily stay an extra step ahead with the freedom and flexibility brought to you by the Strike Industries Anti-Rotation Castle Nut and Multi-Function End Plate.
The Multi-Function AR End Plate (MFEP) allows you to choose your preferred sling type. Whether you use a hook and loop, traditional sling loop or you need a quick detach socket, they’re all here. You’re not married to one or another and you can change as often as you like without changing the end plate. Add this to the easy removal of the Anti-Rotation Castle Nut and your AR system is now an ultra-flexible weapon system that you can retool for whatever the future holds. Stay ahead of the competition, and Strike First.

Write a Review

9 Reviews

  • Amazing End Plate

    Posted by Matthew on 21st Jul 2019

    This plate and castle nut are nearly perfect. Nice matte color, and very durable finish.

    One of the minor issues I have is how sharp the edges are, not like they'll cut you but they will tear up some softer metal clips real quick. Also the side I have facing out had a rust spot that was covered poorly with a sharpie I assume, it rubbed off with isopropyl not real happy about that but not the end of the world.

    Overall this thing is amazing and will buy one for all future rifles. First time using wingtactical and they were great, shipped and received super quick, great pricing, will be buying from again.

  • Very nice

    Posted by Richard F on 5th Jun 2019

    This thing looks great, is easy to install, and NO staking. Yes, the little spring retainer screw is challenging to put in. But not worth a star subtraction. Obviously lock-tight those little screws!

  • Great product

    Posted by Unknown on 24th Mar 2018

    Another great product from Strike Industries. nice that you don't have to stake anything definitely happy with my purchase here.

  • Cheap metal

    Posted by Grunt on 29th Jan 2018

    I purchased this because i liked all the sling mounting options. After I properly torqued it down the castle nut it just snapped in half. The metal feels cheap and of poor quality also the small screws are a pain. Go with the PWS Ratchet Lock system as it's much stronger and easier to mount. *This is garbage.

  • Awesome and a better castle but it there

    Posted by Daren Dowsett on 10th Jan 2018

    This is my second one I bought and just freaking love this, will diff. Buy again and the price was spot on. Thanks again wing tactiacl

  • Works great!

    Posted by Madclown351 on 2nd Jan 2018

    Someone complained about having to remove material to get this to fit I’m not sure why but on my phase 5 tube attached to a seekin lower and Spike jack lower they work great!

  • Innovative design

    Posted by Mark on 3rd Nov 2017

    Very Innovative design. Works great.

  • Great product

    Posted by Dave K. on 31st Jul 2017

    This product is awesome. So glad I don't have to stake my castle nut anymore. It is a much smarter design than standard mil-spec castle nut. The ratchet locks up tight and it is easy to remove if you want to switch out your receiver extension (a.k.a. buffer tube). Having multi-function sling mount is a plus. Can't go wrong with Strike Industries' products.

  • Needs manufacturing revision

    Posted by Jose on 30th Jul 2017

    Principally bought this endplate for it's QD feature, but liked the versatility of other sling mount options. Having bought other SI products, I had no reservations, but this one sucks. Starting with having to Dremel down the tab that sits on the inside of the buffer tube ring to get it to fit around any of my buffer tubes. Once I got that done, I had to look through several of my local hardware stores for a hex wrench small enough to fit the takedown pin detent spring screw, because SI does not provide one. Finally got the thing installed and tried out the QD mount. I have a few slings from $35-$80, and all of them got stuck inside the QD mount, requiring two handed removal and much effort. And now that I've dremeled the endplate, I can't return it. I think I'll stick with the Tactical Link Z-360.

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