Tapco Castle Nut Features The Tapco Castle Nut is precision engineered to Mil-Spec standards ensuring a secure and reliable fit on standard AR platform buffer tubes. Made from steel and finished in black anodizing it resists corrosion while standing up to the torque and vibration generated during normal firing. The nut threads onto the receiver extension and locks the buffer tube assembly in place preventing it from backing out or loosening over time. Its Mil-Spec dimensions mean it drops in on most standard AR-15 lowers without requiring any special fitting or modification. A castle nut is a small part but a critical one since a loose buffer tube can affect stock stability and overall reliability of the rifle. This component is ideal for builders assembling a lower receiver from parts as well as armorers replacing a worn or damaged castle nut during routine maintenance. Installing it correctly with a castle nut wrench and the proper torque ensures the stock stays rigid and the action cycles reliably. Affordable and essential this Tapco Castle Nut is a practical addition to any AR builder s parts bin for sale at GrabAGun. Tapco Castle Nut Specifications Manufacturer: Tapco Model: Castle Nut Compatible Hosts: AR Platform Color: Black Material: Steel Finish: Anodized Weight: 0.25 lbs Available At: GrabAGun