The Fortis Lightweight Enhanced K2 castle nut and end plate in black is a two-piece system that keeps an AR-15 castle nut from backing off, with no staking required (Fortis part no. LE-BLK-K2-BLK). A locking lever on the castle nut slots into the end plate and engages notches cut into the nut, so the two lock together in a single clean motion. Fortis Manufacturing machines both pieces from aircraft-grade aluminum, and the pair weighs about half an ounce. It is a good fit for builders who swap buffer tubes or stocks often, because the nut comes off without destroying a staked end plate. The end plate also carries a quick-detach sling socket.

Key Specifications

• Both the castle nut and the end plate are 7075-T6 aircraft-grade aluminum, a strong alloy that keeps the pair light.
• The locking method is the K2 locking lever, which slots into the end plate and engages notches on the castle nut.
• Together the system weighs 0.53 ounces (15 grams), adding almost nothing to the back of the rifle.
• The end plate has a quick-detach socket with a 360-degree rotational locking interface for sling attachment.
• There are no set screws or ratcheting parts, so nothing is single-use and the system can be reinstalled.
• The color is black, a finish that suits most AR-15 builds.
• The set is made in the USA by Fortis.

Frequently Asked Questions

Do I need to stake the castle nut? No. Fortis designed the K2 system so the locking lever holds the castle nut in place without the traditional staking of the end plate.

What is included? The product is a lightweight castle nut and end plate system in black, with the K2 locking lever mechanism.

Can I remove it later? Yes. Because it has no set screws or ratcheting parts, it can be removed and reinstalled when you change buffer tubes.

Buy the Fortis Lightweight Enhanced K2 Castle Nut & End Plate, Black

If you have fought a stubborn staked castle nut, the K2 system is the cleaner answer. Order it from our Lubbock, Texas gun shop for fast, insured shipping, and explore more AR-15 buffer system parts for the rest of your build.