Suit for use in hardness under 28 artifacts, Such as Stainless steel , iron plate, aluminum, wood
You can use water to cooling it when it is work and it can be used for even longer
Size 4 32mm,6 24mm,4 22mm,3 12mm,4 12mm
No need of center punch.Compared with the ordinary twist drill,it is not easy to break and it can be used for deburring, chamfering and open hole on Wood metal plastic