Use this T-handle tap wrench, with our high carbon steel taps. It will accept taps from #0 to #8 in diameter in the recessed fingers in the jaws. Never use high speed steel (HSS) taps for gunsmithing. High speed steel is perfect for a drill bit, but a poor choice for a gunsmith's tap. If broken, it is difficult to remove. Our high carbon steel taps are hard and sharp. If broken they are easily removed with a drift punch.