Sand Casting

Classification of sand casting

Sand casting can be divided into three types according to molding sand:

1. Green sand casting: Green sand casting refers to the method of using the moist sand as the mold, normally it’s silicon sand. For a long time, wet sand casting has been the basic technology in foundry production.

2. Resin sand casting: resin sand is a mixture of quartz sand and resin, which plays a barrier role between casting and molding sand, preventing sand sticking and preventing high temperature liquid metal oxidation.

3. Precoated sand casting: Precoated sand refers to the mold sand or core that is covered with a layer of solid resin film on the surface of sand particles before molding. Compared with the other two sand casting methods above, precoated sand casting is more precision and has better surface, which is usually used to produce small parts.

How to form castings with sand molds

Sand casting process steps:

1. Pattern making: according to the drawings to make the mold, the mold is divided into wood mold, metal mold, foam mold and so on according to the material.

2. Core making: core box is used to make mold core, which can form the internal shape of casting.

3. Sand molding: molding sand is used to form the mold cavity of the casting. Molding is the key to casting.

4. Melting and pouring: according to the required metal chemical compositio, the alloy material is melted in a suitable melting furnace to form qualified liquid metal. Then the molten iron is injected into the molds to fill the whole cavity.

5. Cleaning: shake off the sand on the surface of the casting, and shot blasting the casting to make the surface smooth.

Is sand casting fit for you?

Sand casting is widely used in industry. In all casting production, sand casting accounts for nearly 70%, and most of them are green sand casting. It will be your best choice if your parts meet the following requirements:

1. Low production cost and simple production process

2. Short production cycle

3. There is no restriction on the shape of parts, and complicated design can be cast

3. It can produce large workpieces with casting weight of more than ten tons

Almost all metals can be cast, such as gray iron, ductile iron, steel alloy, copper alloy, aluminum alloy, etc

5. Flexible production quantity, suitable for small batch production

In addition to the above advantages, we must also understand its disadvantages. Compared with investment casting, the surface of sand casting is rough and the tolerance is around CT11.

From ferrous metals to nonferrous metals, sand casting can cast almost all metal grade. Maple machinery can cast parts in the following materials.

• Grey Iron、Ductile Cast Iron、White Cast Iron、High Cr Cast Iron
• Carbon Steel、Alloy Steel、Stanless Steel
• Aluminum