Sand casting is preferred for machine tool bed castings, mainly due to its lower cost, simpler production process, and shorter production cycle compared to other casting methods. When the wet mold cannot meet the requirements, consider using clay sand surface dry sand mold, dry sand mold or other sand molds. The machine tool bed frame castings are manufactured according to GB9439-88. Resin sand molds have good rigidity and high initial strength during casting, which allows for the use of graphitization expansion during the solidification process of cast iron to eliminate shrinkage and porosity defects, achieving less riser and no riser casting of gray cast iron and ductile iron parts.

Characteristics of castings

① The bed casting has good performance and shock absorption. Due to the favorable lubrication and oil storage properties of graphite in cast iron, it has good properties. Similarly, due to the presence of graphite, the shock absorption of gray cast iron is superior to that of steel.

② Good process performance. Due to its high carbon content and eutectic composition, gray cast iron has a relatively low melting point, good flowability, and low shrinkage rate, making it suitable for casting complex or thin-walled bed castings.

The blank is generally manufactured by casting method. Currently, most measuring tool castings are made by sand casting. For small measuring tool castings with small size and high precision requirements, special casting methods such as casting, investment casting, and centrifugal casting can be used. The selection of raw materials for mechanical processing of casting measuring tools is a very important step. The selection of raw materials for measuring tools does not affect the processing technology and cost of the raw materials, but also affects the processing method and quality of the mechanical processing. Therefore, it is necessary for process personnel in both casting and machining of measuring tool blanks to closely cooperate and reasonably determine the type and structural shape of the blanks. Measuring tool blanks are generally manufactured by casting. At present, most measuring tool castings are made using sand casting. For small measuring tool castings with high requirements for small size and precision, special casting methods such as sex casting, casting, pear casting, investment casting, and centrifugal casting can be used.