Luth-AR Carbine Lock Ring / Castle Nut

Luth-AR Carbine Lock Ring / Castle Nut

Built to deliver dependable strength where it matters most, this Carbine Lock Ring / Castle Nut is a rugged, no‑nonsense component engineered to keep your carbine‑style rifle solid and secure. Machined from durable 4140 steel and finished with a protective manganese phosphate coating, it’s designed to withstand repeated use, harsh environments, and the constant stress of recoil.

Whether you’re completing a new build or upgrading an existing platform, this lock ring ensures your buffer tube stays firmly retained against the lower receiver—providing the stability and reliability every shooter expects from their rifle. Simple, strong, and purpose‑built, it’s an essential part of any carbine setup.

4140 Steel Construction
Provides exceptional strength and long‑term durability under repeated firing and field use.

Manganese Phosphate Finish
Offers corrosion resistance and a non‑reflective surface ideal for duty or tactical applications.

Built for Hard Use
Engineered to handle the rigors of regular shooting, training, and environmental exposure.

Specifications

• Material: 4140 steel
• Finish: Manganese phosphate
• Compatibility: AR10, AR15, M-16, Carbine