AR-15 Barrel Nut

Standard AR-15 Barrel Nut

The barrel nut threads onto the front of an AR-15 upper receiver and clamps the barrel extension in place, so it is one of the parts that sets how securely the barrel is held. This United Defense nut follows the familiar standard pattern, with a toothed flange at the front and internal threads at the back. Builders assembling a new upper and owners replacing a worn or damaged nut are the people who reach for it.

Features

• Castellated Toothed Flange — A ring of raised teeth around the front edge gives an armorer's wrench something to grip while you torque the nut down.
• Gas Tube Clearance — The gaps between the teeth let the gas tube, the thin pipe that carries gas back to the bolt carrier, pass through once one gap is lined up with the receiver's gas tube hole.
• Internally Threaded Body — Fine threads machined inside the rear of the nut screw onto the matching threads on the front of the upper receiver.
• Machined Inner Shoulder — A stepped lip inside the flange end bears against the barrel extension and holds the barrel tight to the receiver.
• External Groove — A machined groove circles the rear of the body near the threaded end.
• Black Finish — The nut has an even black finish that matches the rest of a standard AR-15 upper.
• Standard AR-15 Pattern — The traditional profile is meant for builds using a standard handguard setup rather than a free-float rail with its own proprietary nut.
• United Defense Manufacture — Made by United Defense, a commercial maker of AR-15 parts.

Fit And Installation

Fitting this nut takes an AR-15 armorer's wrench and a torque wrench, with the upper receiver held in a vise block. Torque to the barrel and receiver manufacturer's specification, then turn the nut further until a gap between the teeth lines up with the gas tube hole. Check that your handguard or rail is designed for a standard barrel nut before you order, because many free-float rails ship with a nut of their own.