Among all casting production, 60% -70% of castings are produced using sand molds, and about 70% of them are produced using clay sand molds. The main reason is that sand casting has lower costs, simpler production processes, and shorter production cycles compared to other casting methods. So castings such as engine cylinder blocks, cylinder heads, and crankshafts in cars are all produced using clay green sand technology.

When the wet type cannot meet the requirements, consider using clay sand surface dry sand type, dry sand type, or other sand types. The weight of castings cast with clay green sand can range from a few kilograms to tens of kilograms, while castings produced with clay dry mold can weigh tens of tons. Generally speaking, for medium and large castings, cast iron can be produced using resin self hardening sand molds, while steel castings can be produced using water glass sand molds to obtain castings with precise dimensions and smooth surfaces, but the cost is relatively high.

Of course, the precision, surface smoothness, material density, metallographic structure, mechanical properties, and other aspects of castings produced by sand mold precision casting are relatively poor. Therefore, when these performance requirements of castings are higher, other casting methods should be used, such as investment casting (wax loss) casting, die casting, low-pressure casting, and so on.

The casting method should correspond to the production batch, such as sand casting. Factories that produce in large quantities should create conditions to adopt more technically advanced molding and core making methods. The production line of old-fashioned shock-absorbing or shock-absorbing molding machines has insufficient productivity, high labor intensity of workers, and high noise, which is not suitable for the requirements of mass production. Therefore, it should be gradually transformed. For small castings, a box less high-pressure molding machine production line with horizontal or vertical parting can be used, which has high production efficiency and less footprint for solid molding; For medium components, various box high-pressure molding machine production lines and air impact molding lines can be selected to meet the requirements of fast and high-precision molding production lines. The core making method can use efficient core making methods such as cold core box, hot core box, and shell core. Medium batch large castings can be considered for resin self hardening sand molding and core making. For heavy castings produced in small batches, manual shaping is still an important method. Manual shaping can adapt to various complex requirements and is relatively flexible, without requiring many process equipment. It can apply water glass sand molds, VRH method water glass sand molds, mailing ester water glass self hardening sand molds, clay dry molds, resin self hardening sand molds, and cement sand molds, etc; For heavy castings produced in a single room, the pit molding method has low cost and fast production. The use of multi box and split box molding methods is more suitable for batch or long-term production of standardized products. Although molds, sandboxes, and other materials may require high initial investment, they can be compensated for by saving molding time and improving product quality. Low pressure casting, die casting, centrifugal casting and other casting methods are only suitable for mass production due to the high cost of equipment and molds.