Sand Casting vs Die Casting for Brass Components: Which Process Should You Choose?

At Hansheng Automation, we often encounter customers who have their own drawings but are unsure which casting process to use. For us as a manufacturer, different manufacturing processes mean variations in cost, lead time, and production complexity.

Which casting process should you use?

Take brass (or copper alloy) components as an example. For such parts, there are two relatively mature casting processes to choose from: sand casting and die casting. However, making the actual process selection requires multi-dimensional consideration.

This article will provide you with a detailed overview of the specific differences between sand casting and die casting when applied to brass alloys, covering aspects such as tooling costs, dimensional tolerances, lead times, and more. If you already have some familiarity with these processes, you may proceed directly to the process comparison section.

Sand casting is the oldest and most widely used method for producing brass components. The process works by packing a sand mixture around a pattern of your part to form a mold cavity, then pouring molten brass into that cavity to create the final shape.

At Hansheng, we work with three types of sand molds depending on the application:

Green sand molds - the most common and cost-effective option, using a mixture of silica sand, clay, and water. Well-suited for most standard brass components.

Resin sand molds - offer better dimensional stability and surface finish than green sand. Recommended for parts with tighter geometry requirements.

Water-glass sand molds - a sodium silicate-bonded system that provides excellent heat resistance, often used for larger or more complex geometries.

Once the brass alloy is melted and poured, the sand mold is broken away after cooling. The casting then goes through a series of post-processing steps: gate removal, grinding, shot blasting, and - depending on your specs - surface treatment and dimensional inspection.

Process advantage

• Sand casting can achieve complex structures. Undercuts, hollow sections, large wall thickness variations, and non-uniform shapes are all achievable.
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• Tooling cost is relatively low. It is suitable for prototyping and the production of large components.

Die casting forces molten brass under high pressure into a hardened steel mold called a die. The die is machined to tight tolerances and produces parts with excellent dimensional consistency and surface finish directly out of the mold.

However, this process involves higher tooling costs and certain limitations on geometric complexity. A die casting tool for a moderately complex brass component typically runs from $3,000 to $10,000 USD depending on part complexity and cavity count. Suitable for large-scale production needs.

Die casting also constrains your geometry. Parts must be designed with consistent wall thicknesses, generous draft angles, and limited undercuts. Deep cavities and cores (which create hollow sections) are difficult or impossible with standard die casting.

Die casting advantage

• High-volume production of small-to-medium parts with predictable, repeatable geometry. Connectors, fittings, valve bodies in standard configurations, and housings produced in the tens of thousands-particularly for products requiring such annual volumes.

• The per-unit cost at volume is significantly lower than sand casting, and the as-cast surface finish often requires minimal post-processing.

The table below provides a comparison of several key dimensions between these two processes for brass components, which we have compiled for your reference. We hope you find it helpful.

As a knowledge extension, we would like to introduce two brass alloys commonly used at Hansheng: C86300 Aluminum Bronze and C93200 Tin Bronze. Both of these alloys exhibit favorable performance characteristics under the aforementioned casting processes and are common grades within the brass family.

C86300 - Aluminum Bronze

C86300 is a high-strength manganese bronze containing aluminum, iron, and manganese. Its tensile strength reaches approximately 758 MPa with a Brinell hardness of HB 223–270 (ASTM B505/B505M).Common operating conditions involve high mechanical loads (e.g., gears, worm wheels, cam followers), high wear, and fatigue loading.

C86300 sand casts very well. Its high alloy content means it requires careful temperature control during pouring, but the resulting casting is dense and mechanically reliable.

C93200 - Tin Bronze (SAE 660)

C93200 is a leaded tin bronze widely used for bearing and bushing applications. With a tensile strength around 207 MPa and a relatively low hardness of approximately 60–65 HBW (ASTM B505/B505M). The tin provides corrosion resistance in water and mild chemicals.

Common applications for C93200 include:

• Plain bearings and sleeve bushings in hydraulic and pneumatic systems
• Valve bodies and seats in water, steam, and mild chemical service
• Pump housings where corrosion resistance and machinability both matter

This alloy can be processed using either sand casting or die casting; however, for custom requirements or low-volume production, sand casting is generally the preferred method.

Quick selection

If your application sits between these two profiles, our engineering team can review your drawings and operating conditions to make a specific recommendation before you commit to tooling.

After providing a detailed introduction to both processes, we will use our own quality control practices as an example to illustrate how to evaluate a supplier's quality management capabilities.

At Hansheng, every brass casting order goes through the following sequence after cooling and demolding:

1. X-Ray Flaw Detection

Internal porosity, shrinkage cavities, and inclusions that are invisible on the surface are identified using industrial X-ray inspection. This step is standard on structural components and critical-use parts.

2. Surface Treatment

Depending on your application, parts may undergo shot blasting, grinding, polishing, or chemical surface treatment to achieve the required finish and protect against corrosion.

3. Dimensional Inspection to CT8 – CT10

All castings are measured against the ISO 8062 casting tolerance standard. Our standard output sits within CT8 – CT10, with tighter grades achievable through post-cast machining. If your drawing calls out specific critical dimensions, these are verified individually before shipment.

4. Material Certification

We provide mill certificates and material test reports confirming alloy composition for orders where traceability is required.

If your project has specific inspection requirements - third-party inspection, witness testing, PPAP documentation - let us know at the RFQ stage and we will incorporate these into the production plan.

Hansheng Automation provides brass casting services including sand casting with green sand, resin sand, and water-glass molds, as well as die casting and lost wax casting. Our facility is located in Dongguan.

Request a Quote for Brass Casting →

If you are unsure which process fits your project, or if you are working with a drawing that was not specifically designed for casting, our team at Hansheng is available to review your requirements and make a process recommendation before you commit to tooling costs.

How long does a brass casting order take from drawing to shipment?

For sand casting, typical lead time from approved drawings to shipment is 2 – 4 weeks for standard parts. Complex geometries requiring core making or multi-part molds may take 3 – 5 weeks. First-article samples can often be expedited - contact us to discuss your timeline.

Can you cast custom shapes from our 2D or 3D drawings?

Yes. We design custom sand molds based on your provided drawings. Both 2D DWG/DXF and 3D STEP/IGES files are accepted.

Do you offer post-cast CNC machining?

Yes. As part of our broader manufacturing capabilities, we can machine castings to final dimensional tolerances after casting. This is common for bearing surfaces, threaded features, sealing faces, and other features that require tighter tolerances than casting alone can deliver.

How do I get a quote for custom brass casting?

Send us your drawings (2D or 3D), your required alloy (or application description if you need alloy guidance), estimated annual volume, and any specific quality or delivery requirements. We will respond with a detailed quotation within 2 business days.