The 1/4 inch drive sockets (Length 25mm) have a bi-hex socket (12 point) end and are made from chrome vanadium steel with a high chrome finish. The OGV profile allows for tightening torque to be applied to the sides rather than to the angles of the nut. These sockets are for manual use only. ASME B 107-1, ISO 1174-1.Select Option 1/2in3/16in3/8in7/32in9/16in9/32in Add to Basket Quantity