Why do platforms need to scratch research

Everyone knows that cast iron platforms are used for power experiments and equipment debugging of machinery and engines. They have T-shaped grooves on the surface and can be used to fix experimental equipment. All cast iron platforms need to be manually scraped and ground to achieve our ideal accuracy, because all machine tools will have errors due to their own accuracy problems or tool wear. Only manual scraping and grinding can artificially control and inspect the accuracy of the platform.