1) The diameter of the drill used cannot exceed the allowable value of the electric drill.
2) The drill bit must be clamped with a key, and other tools are not allowed to hit the drill chuck.
3) Do not use too much force when drilling to prevent motor overload. If the speed is found to be reduced, the power supply should be cut off immediately for inspection.
4) The sporadic processed parts must be firmly on the fixture.
5) Do not wear gloves.