Standard Length 12-Point Sockets, 3/8” Drive, Metric (SOCKET 3/8-DR 21MM 12PT)

SOCKET 3/8-DR 21MM 12PT|Armstrong’s sockets feature a unique radius design that exerts force on the flats of fasteners—which means not only do you get more torque, but the corners don’t get rounded with use. The sockets have deep openings that are chamfered to slip easily over fasteners, seat squarely and hold securely. They are precision cold-formed of special steel and hardened for extra strength, permitting a thin wall design that works well in tight spots. The drive end is also chamfered and notched on all four sides so the drive tang slips in smoothly and locks in any position.