The Wheeler Engineering Delta Series AR Combo Tool covers most AR-15 service jobs with one tool: barrel nut, buffer tube castle nut, fixed-stock buffer tube and flash hider.
It is built from layered, laminated stamped steel, which lets it carry hardened steel barrel nut pins rated for the heavy torque a barrel install calls for. A 1/2" square drive cutout lets you run it on a torque wrench or ratchet, so you can hit spec instead of guessing.
Features:
Before you use it: clamp the upper or lower in a proper vise block, not the tool, and check your barrel and buffer tube manufacturers' torque specs. Confirm your barrel nut is a standard mil-spec pattern; many free-float handguards ship with a proprietary nut that needs its own wrench.