Spiral flute tap is a tool for machining thread.  It belongs to a kind of tap, because its chip groove is named spiral.  Spiral flute tap is divided into left - hand spiral flute tap and right - hand spiral flute tap.  The geometric parameters of spiral tap mainly retain spiral Angle, chip sink, front Angle and back Angle.  Spiral flute tap has the advantages of long life, high efficiency and low cost, good cooling and lubrication conditions, smooth Cutting and easy to enter the buckle and small torque.  Spiral flute tap is one of the most commonly used tap, according to different working conditions with different spiral angles, the common is right-hand 15° and 42°.  Generally speaking, the larger the spiral Angle, the better the chip removal performance.  Suitable for blind hole machining.  It is best not to use for through hole processing