Sand casting projects involve many steps, and each one influences quality, cost, and delivery time. For buyers, knowing how a supplier manages these steps makes it easier to set expectations, prepare documents, and avoid delays. A well-organized project turns drawings into reliable components with minimal back-and-forth. Matech, a professional custom casting manufacturer in Shanghai, handles sand casting projects from pattern development through machining and finishing, offering customers a clear, structured workflow and single-point responsibility for the entire production process.

Project Review and Quotation

Every project begins with a thorough review of the customer's drawings or samples. Engineers examine part geometry, material grade, tolerances, machining requirements, and expected volumes. They identify potential casting challenges and suggest design adjustments where helpful. This early review leads to an accurate quotation and realistic lead time. Buyers who supply complete information at this stage avoid revisions and keep the project moving smoothly from the very beginning.

Pattern and Tooling Development

Once the order is confirmed, pattern and core box tooling is designed and produced. Patterns include allowances for shrinkage and machining, while core boxes create internal features. CNC machining ensures accurate tooling dimensions. This stage usually takes several weeks and is critical to consistent casting quality. Approving tooling designs promptly and avoiding late drawing changes help maintain the planned schedule.

Molding and Pouring

With tooling complete, molds are produced using automatic molding lines or resin sand, depending on part size and volume. Cores are placed, molds are closed, and molten metal is poured after its composition is confirmed. Automatic lines provide consistency and speed for repeat production, while resin sand suits larger or more complex parts. Careful control of sand, temperature, and pouring speed helps prevent defects.

Cleaning and Heat Treatment

After cooling, castings are removed from the molds, and gates and risers are cut off. Grinding and shot blasting clean the surfaces. Heat treatment may follow to achieve required properties or relieve stress. This stage prepares castings for inspection and machining. Proper cleaning also reveals surface condition clearly, allowing inspectors to identify any issues before further work is done.

Inspection and Sample Approval

For new projects, first castings are inspected thoroughly and often sent to the customer as samples. Dimensional reports, material certificates, and hardness results accompany them. Customers test the samples in their equipment and provide feedback. Approval of samples confirms that tooling and processes are correct, giving both parties confidence to move into full production.

Machining and Finishing

Most sand castings require CNC machining on critical features. Fixtures are prepared, programs are set, and machining brings bores, faces, and threads to final dimensions. Dimensional inspection confirms accuracy. Surface treatments such as painting, powder coating, or electrophoresis are then applied. Completing these steps in-house shortens lead times and ensures components arrive ready for assembly.

Delivery and Ongoing Support

Finished parts are packed to protect against damage and corrosion during shipping, with documentation including inspection reports. After delivery, ongoing communication allows the supplier to address feedback and improve future batches. Repeat orders benefit from existing tooling and established processes, reducing lead times. A well-managed sand casting partnership delivers consistent quality, predictable schedules, and long-term value for industrial buyers.