Fortis Manufacturing
Overview
The Fortis Light Weight K1 Castle Nut and End Plate is designed from 7075-T6 aluminum and features a hardcoat anodized finish for added durability. This enhanced type castle nut and end plate set provides a secure attachment point for the buffer tube, ensuring stability during operation and minimizing slippage. You'll often find this product in builds utilizing a mid-length gas system chambered in 5.56 NATO, making it a practical choice for those configurations.
Fortis Light Weight K1 Castle Nut and End Plate Black, Gray - LEBLKK1GRY
Builders on GunPartPicker first added the Fortis Light Weight K1 Castle Nut and End Plate Black, Gray - LEBLKK1GRY to a build in February 2026.
It was in stock most days in August 2026, and today all 3 retailers we track have it in stock. Prices barely moved in August 2026, holding around $37.95, so there haven't been real sales lately. Buying today, the lowest price is $37.95 at BattleHawk Armory, which matches the best price we saw in August.
Updated · from real builds on GunPartPicker · Prices checked · refreshed daily across 35 retailers
Builds in the community that include the Fortis Light Weight K1 Castle Nut and End Plate Black, Gray - LEBLKK1GRY
| Build | Parts | Total |
|---|---|---|
 | 18 | $1234.97 |
 | 21 | $2608.99 |
 | 24 | $3799.45 |
 | 35 | $3398.46 |
 | 29 | $4990.03 |
 | 18 | $2162.56 |
 | 16 | $1238.81 |
 | 20 | $1512.64 |
 | 27 | $2199.44 |
 | 22 | $1414.51 |
2 global ratings
Top reviews
Fortis K1 castle nut and end plate combo in gray is a unique color option. The lightweight castle nut is hollowed out which saves a couple grams. End plate has the integrated QD point. Took the standard AR15 wrench just fine, torqued to spec.
Fortis K1 lightweight castle nut and end plate in gray is a unique color option. Castle nut has the larger wrench notches for easier torquing. End plate has integrated QD socket. Anti-rotation flange seats correctly. Gray accents work well.
