1. Before tapping, find out the specifications of the threads according to the requirements of the drawings and select the taps of the same specifications.
2. Check whether the size of the bottom hole meets the specifications and whether the bottom hole is chamfered.
3. When tapping the thread, the calibration part of the tap cannot be fully tapped.
4. Coolant must be added to tapping.
5. The workpiece must not be skewed when tapping.