1. The workpiece is not clamped, and the workpiece is loose during sawing.
2. The saw blade is too tight or too loose.
3. The sawing pressure is too large or the sawing force suddenly deviates from the direction of the saw seam.
4. Forcibly correct the skewed saw seam, or after replacing the new saw blade, it is still sawing off the original saw seam too violently.
5. When sawing, the saw blade is partially worn in the middle, and when it is stretched and sawing, it is stuck and broken.
6. When stopping use in the middle, the hand saw is not taken out from the workpiece and breaks.