1,)To prevent screw flat,it must be use special free pliers to screw drill bits or reamer,do not use pipe tongs.Also do not let the pliers teeth crushing the cutting edge or fracturing the carcass.
2,)There should be no clutter in the hole.
3,)To prevent the deciduous core destructed the drill bit’s cutting edge,Lift the drill into the hole,do not drag in the ground ,and falling slowly when drill-down.
4,)It should be press lightly,and rotate slowly after the drill bit down to the hole bottom.After appropriate drilling 0.2m-0.3m then normal drilling.
5,)To prevent blocking the core,It is not allowed to lift the drilling tool during the normal drilling process.
6,)To prevent burning the drill,It must be ensure the flushing fluid circulation.
8,)With lightly pressure and slowly rotate speed while sweeping the hole.
9,) if not hear the normal vibration sound or drill too slow during drilling, lift the drill to check without delay.
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