AR-15/M-4 Buffer Tube Castle Nut

The M4 Castle Nut is used to secure the receiver extension, also known as the buffer tube, to the rear of an AR-15 receiver. It is also used on some stock kits for other weapon, such as shotguns, where AR-15 buffer tubes are being attached to receiver adapters. It is tightened using a spanner wrench, stock wrench or AR-15 armorers tool designed for this purpose. Our Castle Nuts are made to Mil-Spec standards and have 4 wrench notches used for tightening and 3 staking notches on the opposite side for staking the nut in place once the stock is assembled if desired. These castle nuts are high quality steel, made to precise standards for a tight fit on a quality buffer tube and have a mil-spec parkerized finish.

Thickness: .370", Weight: .60 ounces.