1. Failure to install molds according to standard operating procedures.
2. Failure to wipe the machine tool workbench clean or waste materials on the workbench.
3. The upper and lower surfaces of the mold were not wiped clean.

1. The parallelism and verticality of the workbench and slider of the machine tool exceed the tolerance.
2. The parallelism and verticality of the upper and lower pads of the machine tool exceed the tolerance.
3. The slider is not properly adjusted.

1. The parallelism of the upper and lower planes of the mold exceeds the tolerance.
2. Uneven height of travel limiter.
3. Uneven punching clearance.
4. The centerline of the convex and concave molds does not coincide.
5. The internal travel device is worn out.

1. The size of the material is relatively small.
2. The material has poor fluidity.