The Distinction between Sand and Metal Casting  

Sand casting literally is a casting method with sand as a moulding material, and is a traditional casting process, which generally uses gravity casting, and low-pressure or centrifugal casting for special requirements.

Sand casting’s application is very broad. The mold used, initially wood, but now changed to aluminum alloy mold or resin mold due to some drawbacks. Compared with metal casting, sand casting has advantages, such as low price, high fire resistance, but still shortcomings.

The main raw material of metal casting is heat-resistant alloy steel. Metal casting is a modern casting process, and generally uses gravity casting and pressure casting. However, metal casting is not suitable for small-lot and large production, and not for copper alloys, but applied to castings of aluminum, zinc and magnesium.

Now let me introduce the advantages and disadvantages of metal casting and sand casting in details:

Advantages of metal casting

1. The metal mold has a faster cooling rate and a denser structure of the casting, which can be strengthened by heat treatment, and its mechanical performance is about 15% higher than that of sand casting.

2. The casting quality of metal casting is stable, the surface roughness is better than sand casting, and the scrap rate is low.

3. Good working conditions, high productivity, easy for workers to master.

Disadvantages of metal casting

1. The metal type has large thermal conductivity and poor filling ability.

2. The metal type itself has no air permeability. Corresponding measures must be taken to effectively exhaust.

3. The metal type has no retreat and is easy to crack and deform during solidification.


Advantages of sand casting

1. Compared with other casting methods, sand casting has lower cost, simple production process and short production cycle.

2. Because the molding materials used in sand casting are cheap and easy to obtain, the mold is easy to manufacture, and it can be adapted to single-piece production, batch production and mass production of castings.

Disadvantages of sand casting

The quality of molding sand and core sand directly affects the quality of castings. Poor quality of molding sand will cause defects such as pores, sand holes, sand sticking, and sand inclusion in the casting.

How to Distinguish Good Sand Molding for Casting

How to Distinguish Good Sand Molding for Casting

sand casting molding from Yide casting

sand casting molding from Yide casting

The material used to make molds for casting is called molding material. The molding material used to make sand mold is customarily called mold sand. And the material used to make sand core is called core sand. Generally, mold sand is made from a mixture of raw sand with 9% clay and 6% water. In some cases, adding a small number of additionals such as coal powder, vegetable oil and wood chips can improve the performance of mold and core sand. The quality of mold and core sand directly affects the quality of the casting. Bad quality of mold sand will cause defects such as pores, sand eyes, sticky sand, and sand inclusion in castings. The molding sand of quality should have the following properties:


  1. The breathability of Sand Casting Molding

When the high-temperature metal liquid is poured into the mold, it will be filled with a large amount of gas, which must be vented out. Thus, a good sand mold for casting needs to have a good breathability,  which is a property of letting the gas go out through the cavity.

Otherwise, the casting will produce pores, misrun and other defects. The factors affecting the density of the mold includes grain size, clay content, moisture content and mold compaction. The finer the grain size, and the higher the clay, moisture content and mold compaction, the worse the density.


  1. Strength of Sanding Casting Molding

Sand strength means the property of the sand resistance to external force damage. The sand must have sufficiently high strength in order not to cause a collapse in the process of modeling, handling and assembling, and not to damage the cast surface when pouring. The strength of the sand should not be too high, otherwise, it will cause defects due to the density and deformability decline.


  1. Fire resistance

High-temperature melton iron poured into the casting produces a strong thermal effect. And thus the sand must have the property of resisting high-temperature thermal effect. If the molding material has poor fire resistance, the casting is prone to cause burn-on. The higher content of SiO2 and the larger the sand particle, the better the fire resistance.


  1. Plasticity

Plasticity refers to the ability of mold sand to recover to its existing shape after deforming under the action of external forces. The mold operation will be convenient, if the plasticity of molding material is good, and the shape of the mold is accurate, the contour is clear as well.


  1. Deformability

The volume of casting will shrink in the condensation process. Hence the molding sand should have a certain compression capacity. If the deformability of the sand is not good, the casting is prone to cause internal stress or cracking. The tighter the sand, the worse the deformability. Adding wood chips to the sand can improve the deformability.

Yide Casting produces casting irons via sand casting molding, equipped with two automatic production lines imported from Germany, which has a fully complete automatic system like automatic sand pressing machinery parts, automatic melton iron pouring system, etc. – a fully casting production system. Thus Yide Casting can provide high-quality casting products with fast production efficiency.

If you are looking forward to a professional casting plant from China, or you want an OEM service for your casting parts in machinery, please don’t hesitate to contact us for more details.

The Application of Ductile Iron Castings for Pipes

When occurs in the casting market, the ductile iron casting shows its excellent wear resistance feature. In other words, the ductile iron casting plays an important role in the field of wear resistance.  At the same time, the ductile iron casting gets a fast development in different fields. In the following, I will mainly introduce the ductile iron casting pipes.

iron casting pipes iron drainpipe

In the project of drinking water transmission and distribution, ductile iron casting pipes have achieved great success and gained a reputation in the fields of hydraulics, casting and metallurgy. Ductile iron casting sewer pipes and fittings are controlled to minimize damage to the piping system due to external pressure.

grey iron casting valve and iron pipes


The external anti-corrosion measures of ductile iron casting sewer pipes include spraying zinc 130g/m2, coating red anti-corrosion material and using epoxy coating on the socket. The high alumina cement HAC used in the anti-corrosion pipeline contains more than 50% alumina. And the cement lining rich in metal ions, thus provides excellent wear resistance.


At the same time, we use centrifugal spraying technology to spray the inner surface of the tube and make it very smooth. This measure effectively reduce the head loss. In addition, the outer anti-corrosion layer sprayed with red epoxy resin ensures the resistance of the pipe to chemical corrosion.


Whether in municipal or industrial areas, protecting people’s property safety is an important mission of the fire pipeline system. Ductile iron casting pipe has a triple safety factor in design. The design ensures the entire fire protection system, including valves and fire hydrants. Besides, it fully meets the requirements of the fire pipe system.


The requirements of agricultural irrigation on the sealing performance of pipelines are not as strict as drinking water.  Now, with the increasing shortage of water resources and the increase of costs, this concept is changing. In order to ensure long-term impermeability, the agricultural irrigation pipe network must be able to resist soil movement, the passage of agricultural machinery, and any other possible accidents。

YIDE casting has 27 years’ casting experience, is a casting & machining factory, manufactures high-quality iron casting valves and ductile iron casting pipes according to your drawing and parameters, OEM service is available too. If you have casting demands, please don’t hesitate to contact us for more details.

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