QD is a leading manufacturer of investment casting (lost wax casting) and sand casting. We are experts with 20 years of experience. We specialize in providing comprehensive casting services, from design optimization to mass production, for clients in the machinery, automotive, and marine industries. We use our expertise to solve a wide range of casting challenges.
Comparison between investment casting and sand casting
Similarities between lost wax casting and sand casting
| Similarities | Specific Descriptions |
| Nature of the Process | Both are hot – forming technologies in which molten metal solidifies and shapes in the mold. The core is to use the mold to give the shape of metal parts |
| Application Fields | Widely serve the production of metal parts in industries such as machinery manufacturing, auto parts, and aerospace equipment |
| Basic Processes | All include core production links such as metal smelting, cavity filling, cooling and solidification, demolding and cleaning |
The difference between investment casting and sand casting
| Comparison Dimensions | Investment Casting | Sand Casting |
| Mold Material | Wax pattern (recyclable) + High – temperature resistant ceramic shell | Sand – based mold (including various sand types such as quartz sand, resin sand, sodium silicate sand) |
| Part Precision | High (tolerance can reach ±0.05 – 0.1mm) | Medium (tolerance is usually ±0.5 – 1.5mm) |
| Surface Roughness | Low (Ra1.6 – 3.2μm, nearly mirror – like effect) | Relatively high (Ra12.5 – 25μm, subsequent grinding required) |
| Applicable Batch Quantity | Small batch (10 – 1000 pieces), production of multiple varieties | Large batch (more than 1000 pieces), stable production of a single variety |
| Mold Service Life | Wax pattern for single use. Ceramic shell for one – time forming | Sand mold can be reused (service life is about 50 – 200 times) |
Leveraging its dual-process technology and intelligent production equipment. QD can precisely match the process requirements of different products. Ensure casting quality and efficiency throughout the entire process.
Advantages and Disadvantages of Investment Casting and Sand Casting
Comparison of advantages and disadvantages
| Process | Core Advantages | Main Disadvantages |
| Investment Casting | 1. High – precision forming. Reduce subsequent machining 2. Capable of producing parts with complex internal cavities and thin walls (≥0.5mm) 3. Excellent surface quality. No need for extensive grinding | 1. Long mold – making cycle (7 – 15 days) 2. High cost of ceramic shells and special wax materials 3. Low single – shift output. Not suitable for ultra – large – volume production |
| Sand Casting | 1. Mold materials are easy to obtain and low in cost (only 1/3 – 1/5 of investment casting) 2. Short mold – opening cycle (3 – 7 days); 3. Suitable for the production of large – sized parts (weight up to several tons) | 1. Low precision. Require additional machining 2. Prone to sand holes and air holes on the surface 3. Difficult to form complex structures. Prone to filling defects |
Key dimensions of selection
- Part Precision Requirements:
For precision-matched parts
- For gears and valve bodies (tolerance ≤ ±0.1mm), lost wax casting is preferred.
- For non-matching parts such as brackets and bases (tolerance ≥ ±0.5mm), sand casting is more economical.
- Part Complexity:
- Investment casting is recommended for parts with complex internal cavities, curved surfaces, or thin-walled structures, such as turbine blades.
- Sand casting is more suitable for parts with simple structures and regular contours, such as bearing seats.
- Batch Size:
- For small-batch trial production and high-volume customization (10-500 pieces), choose lost wax casting.
- For large-volume, stable production (over 1,000 pieces), choose sand casting. This can reduce unit costs through economies of scale.
- Material Adaptability:
- When casting special materials such as high-temperature alloys and titanium alloys, investment casting is more stable.
- When casting conventional materials such as cast iron and cast steel, sand casting offers a more cost-effective approach.
- Post-Processing Requirements:
- If you want to reduce machining steps (e.g., for medical device parts), choose lost wax casting.
- For parts that require subsequent grinding or drilling, sand casting offers greater flexibility.
QD: Dual process advantage + Full process guarantee
Lost wax casting field – QD’s core advantages
QD has 20 years of experience in precision investment casting. Equipped with imported three-dimensional coordinate measuring machines, spectrum analyzers, and other testing equipment. We can achieve dimensional control to the 0.02mm level. We have delivered over 5,000 sets of complex internal cavity parts for the aerospace and medical industries. Our material qualification rate remains stable at 99.5%. And our wax pattern recovery rate exceeds 85%, effectively reducing customer costs.
Sand casting field——QD’s exclusive service
QD has built a fully automated sand preparation production line. Support 24/7 continuous production. It can cast parts weighing 0.5kg to 3 tons. We provide one-stop services, from mold design and sand mold ratio optimization to post-production shot blasting. We guarantee 100% on-time delivery for batch products. We also help customers reduce production costs by 10%-15% through sand mold formula upgrades.
Whether you need high-precision small-batch parts or large-volume structural parts. QD can be your reliable casting partner with professional technology, customized solutions, and attentive service.
FAQ
1. When is investment casting preferred?
When parts require high-precision fit (tolerance ≤ ±0.1mm), complex internal cavities, or thin-walled structures (wall thickness ≥0.5mm), and batch sizes range from 10 to 1,000 pieces, investment casting can reduce subsequent processing and is more suitable for these needs. Examples include aerospace parts and precision gears.
2. What is the core application of sand casting?
It is suitable for mass production of parts with simple structures and low precision requirements (tolerance ≥ ±0.5mm). This is particularly true for parts weighing several tons each, such as automotive chassis brackets and machine tool bases. Mass production can reduce costs.
3. Does the difference in surface quality between the two processes affect performance?
Yes. Investment casting has a low surface roughness (Ra 1.6-3.2μm). It can be used directly where a smooth surface is required. Sand casting has a rougher surface (Ra 12.5-25μm). For assembly or sealing, additional grinding or machining is usually required.
4. Which process is more economical for small and large-scale production?
For small batches (10-500 pieces), investment casting is more cost-effective. This avoids wasted sand molds. For large batches (over 1,000 pieces), sand casting is the right choice. Through mold reuse and efficient production, the cost per part can be reduced by 30%-50%.
5. Which casting process is suitable for special materials?
For casting special materials such as high-temperature alloys and titanium alloys, the ceramic shell of investment casting offers better high-temperature resistance and more stable molding.
For conventional materials such as cast iron and ordinary cast steel, sand casting offers a more cost-effective method. Material acquisition and handling are also more convenient.