The TEKTON 47773 1/2 in. Drive by 18mm Shallow Impact Socket is constructed of drop forged, heat treated chrome vanadium steel with a durable black phosphate finish to resist corrosion. The hole on socket locks onto drive tang for a sure fit. This socket meets or exceeds ANSI standards. And, don"t worry, it"s backed by the TEKTON lifetime replacement guarantee. So, go ahead, Take It On.