By Coco
When sourcing metal parts for machinery, automotive, aerospace, or industrial applications, choosing the right casting method is essential.
Two of the most common casting processes used by Chinese manufacturers are investment casting and sand casting.
Each method has its own benefits, limitations, price differences, and ideal use cases.
In this guide, we will compare investment casting and sand casting, with a special focus on China-based factories, cost and price analysis, and tips for finding reliable suppliers and foundries.
Contents
What Is Investment Casting?
Investment casting, also known as lost wax casting, is a precision casting method. A wax model is coated with ceramic material to form a mold, which is then heated to remove the wax and filled with molten metal.
This process produces highly accurate and smooth-surfaced metal parts.
Many Chinese investment casting manufacturers and foundries specialize in stainless steel, carbon steel, and alloy steel parts.
These parts are often used in industries that demand tight tolerances and fine detail, such as aerospace, medical, and defense.
What Is Sand Casting?
Sand casting uses a sand mold formed around a pattern.
Once the mold is removed, molten metal is poured into the cavity.
After cooling, the sand is broken away, leaving a rougher-finished part. Sand casting is widely used for larger components and lower-cost applications.
Several Chinese sand casting factories produce engine blocks, machine parts, and heavy-duty components.
Because sand is inexpensive and reusable, this method is cost-effective for large-volume, low-complexity parts.
Key Differences Between Investment Casting and Sand Casting
| Feature | Investment Casting | Sand Casting |
|---|---|---|
| Surface Finish | Very smooth, high precision | Rougher, requires machining |
| Dimensional Accuracy | High | Moderate to low |
| Tooling Cost | Higher (due to wax molds and ceramic shell) | Lower (sand molds are cheap and quick to make) |
| Production Speed | Slower | Faster |
| Material Waste | Low | Moderate |
| Typical Applications | Complex parts, detailed components | Large parts, simple geometry |
| Cost per Part | Higher | Lower |
| Factories in China | Mostly in precision-focused foundries | Widely available in heavy-industry areas |
Price and Cost Comparison
In general, investment casting is more expensive per unit, especially for small batches.
However, for parts that require less machining or finishing, it may save costs long-term.
Sand casting, on the other hand, offers lower upfront costs and faster turnaround times, making it ideal for bulk production of large components.
Chinese suppliers typically quote investment casting parts at $5–$25/piece depending on complexity and material, while sand casting parts range from $2–$15/piece. Pricing can vary based on weight, order quantity, and finish requirements.
How to Choose the Right Supplier or Factory in China
To select the best Chinese manufacturer or foundry:
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Ask for case studies or part samples.
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Confirm ISO certification or other quality standards.
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Compare quotations for tooling and per-unit cost.
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Visit the factory or request a video tour.
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Ensure clear communication regarding tolerances and materials.
Reliable Chinese investment casting suppliers are often based in Shandong, Jiangsu, and Zhejiang provinces, while sand casting factories are found in Hebei and Henan.
Final Thoughts
Whether you’re sourcing from a Chinese foundry for precision parts or low-cost large components, understanding the difference between investment casting and sand casting can save time and money.
Always compare costs, surface finish, and production speed to choose the right method for your needs.
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