Precautions:
1. After the hole opener is installed, it should be idling to debug and observe whether there is any jitter, and then work normally
2. When opening the hole, be stable, please do not apply side pressure and curve drilling
3. It is strictly forbidden to cause high temperature friction in dry drills, which will cause serious wear and affect the use effect
4. When opening the hole, it must be sufficiently cooled and lubricated to reduce product wear and coating shedding
5. When the chip removal is not ideal, please stop working and continue after cleaning