Fortis Manufacturing came up with an enhanced design of the AR-15 castle nut and end plate. They call this new product Lightweight Enhanced (LE™) Castle Nut & End Plate System. The idea behind this system is to provide a secure and robust installation of the two parts minimizing or eliminating the chances of the castle nut to come loose. Let’s take a closer look and see how they accomplished it.

K1 Tapered system

This system uses two methods (K1 and K2) of attaching the castle nut and endplate together. In case of K1 version, there are matching tapered surfaces on the outside circumference of the castle nut and in the inside surface of the end plate. Once the castle nut is tightened, the tapered surfaces provide a snug fit between the two parts. The K2 iteration of this system uses a C-clip that is installed into the groove located at the bottom of the end plate and matches the corresponding cutouts in the castle nut.

K2 C-clip system

Both parts of the K1 system are made of 7075 T6 aluminum and feature a hard coat anodized finish. The end plate of the K2 version is also made of aluminum, however, the K2 castle nut can be made either of aluminum or 4140 steel. The endplates of both systems are available in black color only. The castle nut of the K1 (tapered) system can be ordered either in black or gold color options. The end plates also have a QD sling swivel socket with a 360º rotational locking interface.

Other features of the Lightweight Enhanced (LE™) K1 system and its installation process can be seen in the video published by Fortis (see below).

Both the K1 and K2 versions of the Fortis Lightweight Enhanced (LE™) Castle Nut and End Plate System are available on the company’s website at an MSRP of $39.95.

Images from www.fortismfg.com