Material: Made of diamond, spiral technology, has both toughness and hardness, is not easy to break. The drill bit is sharp, and is easy for chip removal. Applicable machine: Widely used in rotary tool such as hand drills, drill press, flex shafts, bench drill and hanging mill. Application: Fit for drilling small holes on glass, metal, sea shells, jade, pearls, marbles, stones, drywalls and son on. Due to the different hardness of the material, the effect is also different. If you use the drill bit for many times, it will not be very sharp than the first time using. You could cut a little the top of it with plier, it will become sharp again. Note: Add the coolant can increase work efficiency and extend service life. Material Diamond P.
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