AR-15 Pivot Pin

Front Receiver Pivot Pin

The pivot pin is the front pin that holds an AR-15's upper receiver to the lower. Push it out with the rear takedown pin and the two halves separate completely. Push out the rear pin alone and the rifle hinges open on this pin for cleaning and inspection. This United Defense pin is a direct replacement if yours is worn, bent or lost, and it is also a part you need when building a lower from scratch.

Features

• AR-15 Pattern — Made for the AR-15 platform, where it passes through the front lug of the upper receiver and both sides of the lower.
• Hinge Point For Takedown — The upper pivots on this pin when the rear takedown pin is pushed out, so you can open the rifle without fully separating it.
• Flat Head Design — A wide, flat head gives you a firm surface to push against when driving the pin out from the opposite side.
• Black Finish — The dark finish matches the look of a standard black AR-15 lower receiver.
• Cross Hole Near The Tip — A small hole is drilled through the shank close to the tip end of the pin.
• Straight Shank — The smooth, plain shank slides through the receiver holes for normal takedown and reassembly.
• Single Replacement Part — Sold as the pin itself, ready to drop into a build or swap in for a damaged original.
• United Defense Brand — A commercial part from United Defense for home builders and owners maintaining their own rifles.

Fit And Installation

On an AR-15, the pivot pin is held in place by a small spring-loaded detent that sits in the front of the lower receiver. You install the detent and spring first, then press the pin in from the side while holding the detent down. A pivot pin tool or a thin punch makes the job easier and keeps the detent from launching across the room. Only the pin is listed here, so plan to reuse your existing detent and spring or source them separately.