Hansheng Automation (Dongguan) Co., Ltd. is one of the most experienced manufacturers and suppliers of sand casting services in China. If you're going to wholesale bulk cost-effective sand casting services made in China, welcome to get pricelist and quotation from our factory. Also, customized service and OEM&ODM service are available.
Hansheng Automation is an outstanding manufacturer of precision parts casting and processing. At present, we provide customers with a variety of casting services such as sand casting, lost foam casting, investment casting and pouring casting, and also provide finishing services for castings. The following is a brief introduction to our sand casting services. If you need equipment parts casting, lathe parts casting and processing services, please feel free to consult us.
What is Sand Casting?
Sand casting is a metal casting process. It contains several terms. I believe you know what sand casting is after understanding these contents.
1. Sand core
The sand core is actually the product sample needed to make the sand mold. Its shape is the shape of the product we want to cast.
2. Sand mold
The sand mold is divided into upper and lower parts, which are made according to the sample template. Put the sample in the lower sand box, fill and plug the molding sand. After the lower sand mold is made, a layer of parting sand is laid, and then the upper sand mold is made. The upper sand mold needs to be set up with a casting system and exhaust holes. After the upper and lower sand molds are made, the mold can be removed and the sand mold can be repaired. The production of sand molds is a key link in the sand casting process.
Therefore, sand casting is to pour molten metal solution into the pouring system of the produced sand mold, wait for the metal solution to cool and solidify, separate the upper and lower sand boxes, and take out the casting.
features of sand casting services
Strong Adaptability
Suitable for castings of various sizes and shapes, especially suitable for large and complex sand castings.
01
Low Cost
The sand casting process can achieve the production of complex parts at a lower cost.
02
Material Diversity
You can choose ductile iron, gray cast iron, stainless steel, copper alloy, aluminum alloy and other materials.
03
Flexible Surface Treatment
The roughness of the surface will be relatively high after sand casting, and the roughness can be improved by grinding and coating.
04
Easy To Modify
Sand molds are easy to reshape, and design modifications have little impact on tooling costs.
05
Disadvantages
Limitations
Low accuracy (tolerance ± 1.5 mm/m) and relatively high surface roughness (Ra 6–12 μm), suitable for scenarios with low surface requirements.
Low Production Efficiency
A single sand mold is used, not suitable for mass production.
Process of Sand Casting
The process of our sand casting services mainly includes the following steps, which are mold making, molding and core making, pouring, molding, and post-processing. I'll go into more detail about these processes below.
1.Mold Making
According to the casting drawings to make molds, used to form the cavity of the sand mold, the mold can be a wood, metal or plastic mold. The mold parting design needs to be divided along the maximum cross-section of the casting, which is convenient for demoulding after molding.
2.Sand Mold Preparation
Use silica sand, clay, water, and additives to prepare sand molds in a certain ratio.
3.Styling And Core Making
Styling is divided into two categories: manual (flexible, suitable for one-off pieces) and machine (high-pressure moulding machine or 3D printed sand mold). The manual molding method adopts the sand digging method or the loose block method, and the machine molding efficiency can be increased by 3–5 times. The core is formed through the core box, and the complex inner cavity needs to be combined with a sand core (such as a turbine blade cooling channel), and the sand core needs to be embedded with exhaust holes to avoid porosity defects. After modeling, the sand mold is dried (200–300°C for 6–12 hours) to increase strength.
4.Gating System Design
The gating system consists of outer gates, sprues, cross sprues, and inner sprues, and requires smooth transitions to reduce melt turbulence. The riser is designed in the hot joint area of the casting (e.g., at a thick-walled joint), and the top riser can reduce porosity by 30–50%. Air vents and chilled iron (used to adjust the solidification sequence and prevent deformation.)
5.Melting And Pouring
The melting is done using an electric furnace (environmental requirement) or an intermediate frequency furnace, and the temperature of the cast iron needs to reach 1400–1500°C, and the aluminum alloy needs to reach 680–750°C. The flow rate (0.5–1.5 kg/s for grey cast iron) should be controlled during pouring and the ladle should be preheated to 600–800°C to avoid temperature drop in molten metal. After pouring, it needs to be cooled to a stand, and the holding time of thick-walled parts is extended to 2–4 hours.
6.Shakeout And Cleanup
After cooling, the sand mold and the casting are separated by a vibrating shakeout machine, and the old sand is crushed and screened and recovered. The surface of the casting is cleaned of oxide scale and flash burrs are removed (roughness is reduced from Ra 12 μm to less than Ra 6 μm).
7.Inspection And Post-Processing
The castings after molding are subjected to X-ray flaw detection, surface treatment and dimensional measurement (CT8–CT10 class).
There are three main types of sand molds that we commonly use.
|
Sand Mold Type |
Main Ingredients |
Application Scenarios |
|
Green Sand |
Silica sand + clay + water |
General purpose castings (e.g. engine blocks) |
|
Resin sand mold |
Silica sand + furan resin |
High-precision parts (e.g. gears) |
|
Water glass sand mold |
Silica sand + water glass + CO₂ hardening |
Steel castings (e.g. valves) |
The difference between sand casting and other casting services
The core difference between Sand Casting Services and other casting services is that the mold used is a sand mold, which has a great advantage in cost, and I will analyze the difference between sand casting and other casting services for you through a number of comparison factors.
|
factor |
Sand Casting |
Die Casting |
Lost Wax Casting |
|
The material used in the mold |
Sand molds are inexpensive and can be used disposably. |
It is cheaper to use a sturdy metal mold or stamper for high-volume production. |
Wax molds/ceramic shells (single use) are used, which require multi-layer dipping and high-temperature roasting. |
|
Surface treatment |
Due to the coarser surface finish (Ra 6–12 μm) due to the sand structure, additional finishing may be required. |
High-quality, smooth surface (Ra 1–3 μm); No or minimal post-processing is required and additional textured surfaces are available. |
The surface finish is Ra 3–6 μm, and the high-precision parts reduce post-processing. |
|
Thickness of the chamber wall |
It is suitable for parts with a wall thickness of ≥ 3 mm, and the thin wall is prone to defects such as cold insulation and insufficient pouring. |
Thin-walled parts (0.5–3 mm) can be produced with high material utilization. |
Supports complex thin-walled (0.5–5 mm) precision parts such as turbine blades. |
|
Part complexity |
It can handle complex and bulky shapes, but with thicker walls and less precision. |
Suitable for precision construction with high dimensional stability (tolerance± 0.1 mm/m). |
Expertise in complex hollow structures (e.g. jewelry, turbine blades) with tolerances ± 0.5 mm/m. |
|
apply |
It is commonly found in large industrial components, machinery, and buildings that do not have precise details. |
It is used in the automotive, electronic and consumer goods fields where precision and surface quality are critical. |
It is commonly used in the production of aerospace turbine blades, stainless steel joints for medical devices, and precision gears. |
|
Production batches |
Small to medium lot sizes (1–1000 pieces) |
Extra-large quantities (> 100,000 pieces) |
Small to medium to large batches (100–100,000 pieces) |
A commonly used material for sand casting
The sand casting materials commonly used in our factory are gray cast iron HT250 and HT300, ductile cast iron QT200, cast stainless steel AISI 410, cast copper C86300 and C93200, cast aluminum A356 and so on. If you have sand casting needs for other materials, welcome to contact us for a relevant quotation.
Aluminum Investment Casting
Bronze Casting Service
Ductile Iron Castings
Gray Iron Casting
Stainless Steel Investment Casting
Alloy Steel Casting
Sand casting commonly used industries
With its advantages of low cost, strong adaptability, and the ability to produce large-size and complex cavity castings, sand casting is widely used in many industrial fields, especially in construction machinery, automobiles, power equipment and other scenarios.
|
industry |
apply |
|
Aerospace |
Engine block, structural frame, transmission housing |
|
Construction machinery |
Excavator buckets, crane booms, track shoes |
|
Car |
Engine blocks, cylinder heads, transmission housings, motor housings, battery trays |
|
Consumer electronics |
Large appliance frames, heat exchanger housings, equipment housings |
|
Power plant |
Pump housings, valve bodies, wind turbine components, motor housings, compressor housings |
|
Medical equipment |
Equipment base, large diagnostic mechanical frame, durable stand |
|
Communication equipment |
Communication equipment shell, base station shell |
|
Lighting solutions |
Street lamp housings, lamp holders, outdoor lamp housings |
FAQ
Q: What are the key factors that affect the sand casting process?
A: The shape of the part, the choice of casting material, the design of the sand mold and sand core, the design of the cooling system, and whether the surface of the casting sand mold and sand core is smooth are all key factors that affect the sand casting process.
Q: What is the biggest advantage of sand casting over die casting?
A: Die casting is appropriate for sophisticated tasks with great accuracy and limited error ranges, such as automobile component casting. Sand casting's dimensional flexibility allows technology, nevertheless, to be appropriate for manufacturing objects of different sizes. Sand casting mostly offers alloy friendliness and simplicity of usage instead of flexibility or cheap cost. Small batches, bigger, simpler pieces, or unique items created using non-die casting materials call for it.
Q: Is the sand casting process environmentally friendly?
A: Sand casting is an environmentally friendly casting method. When making sand molds and sand cores, we at Hansheng Automation use recyclable silica sand, so that after each casting is taken out, the damaged sand mold can be recycled and redone.
Q: What quality inspections are required for sand castings?
A: Two main quality inspections are performed: X-ray inspection to detect internal defects such as pores, shrinkage cavities, and slag inclusions. Also, dimensional and surface inspections are performed using precision measuring tools to check surface roughness and the removal of burrs.
Q: How should I choose between green sand, resin sand, and water glass sand? What types of castings are suitable for each?
A: Green Sand Molds: These primarily consist of silica sand, clay, and water. They offer low cost and a simple process, making them suitable for general-purpose castings (such as engine blocks), especially for routine parts with low precision requirements and small to medium-sized batches.
Resin Sand Molds: These primarily consist of silica sand and furan resin, offering higher molding accuracy and suitable for high-precision castings (such as gears). This reduces subsequent finishing and is suitable for mechanical components requiring high dimensional stability.
Water Glass Sand Molds: These utilize silica sand, water glass, and CO₂ curing. They offer excellent high-temperature resistance and are designed specifically for steel castings (such as valves). They can withstand the high temperatures encountered during molten steel pouring, preventing mold damage.
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