Explore the evolution and comparison of surface plates in this informative video. Delve into the historical development of surface plates, understanding the shift in preference from cast iron to granite during World War II. Learn about the advantages and disadvantages of both materials, including factors such as flatness and temperature sensitivity. Discover practical insights on using cast iron plates and their role in mechanical accuracy. Gain knowledge about high-precision shop practices and the use of surface plates in welding tables. This comprehensive overview provides valuable information for machinists, engineers, and anyone interested in precision measurement tools.