"Machine and hand taps standard common thread cutting taps. The Chinese are accustomed to high manufacturing precision of high-speed steel teeth called machine tap tap, the carbon tool steel or alloy tool steel roller teeth (or cut teeth) Taps called hand taps actually structure and working principle of the two nut taps is substantially the same. Typically, taps from the working portion and a shank portion. working portion and the cutting portion is divided into the calibration portion, the former mill has Cone, responsible for cutting the work, which is used to calibrate the thread size and shape. "