Hole was cut on the barrier material of tapping operations, the general spiral tap and hand tap difference is that ordinary tap of the hand into a straight groove, while the spiral is a spiral-type tap, tap in the tapping screw to The rotation of the spiral groove can easily rise to iron exhaust hole, so as to avoid residual iron or blockage in the groove, causing tap broken blade crack, it can thus tap growth in the life of the most accurate and cutting The thread cutting tap can be accelerated over straight-slot 30-50%. Spiral Tap for Scope: Cutting high toughness of the material (carbon steel, alloy steel and non ferrous metals), but not for cast iron chip crushing the material into blind hole machining.