1. For diameters of 20 and above, except for electric screwdriver, please choose a circular three handle handle (electric screwdriver can be used because it has button force control that will not exceed the negative phase).

2. Not exceeding the scope of use (with a thickness limit of 5mm for bench drills and within 1mm for hand drills).

3. If stuck, please reverse and remove the hard board, and replace it with a higher power drilling rig. Please slow down the speed.

4. Please press the drill lightly when drilling. If the weight gets stuck, the handle will break.