This holder doesn ' t only meets the requisites of a conventional quick change chuck ( capacity / weight / dimensions ) but also has the advantage of being an excellent tapping device with pre - adjustable torque 显然这种带扭力保护的攻丝夹头适用于各种不同的攻丝操作的平台例如：打盲孔、直径很小的、很坚硬的工件或者是当丝锥损耗的很严重的时候。
