The flatness of die parts can be measured by a dial indicator on a precision marking board. If the workpiece is relatively small, the workpiece can be moved for measurement; If the workpiece is relatively large, you can move the dial indicator for measurement. Similarly, to measure verticality on the scribing board, the workpiece should be clamped on the precision scribing flat pliers, and the parallelism of one side should be measured, then the flat pliers should be rotated by 90 degrees, and then the parallelism of the other side should be measured. The measured workpiece can also be fixed on the milling machine for measurement, and the accuracy of the machine tool can ensure the accuracy requirements of measurement.