The overall size of cast iron plate is 4m × 8m, which can be spliced ​​more than this size. After wearing, it can be repaired again to restore its accuracy. The flatness of cast iron plate can be checked by means of coating method. It is accurate, intuitive and convenient The advantages. After scraping the cast iron plate to promote table seat, the workpiece is relatively smooth, no astringent feeling, convenient measurement, to ensure the measurement accuracy.