Design for Manufacturability: 8 Tips to Optimize Cast Parts

Maintain Uniform Wall Thickness

Ensure consistent wall thickness throughout the part to promote even cooling and reduce defects like shrinkage, porosity, or warping. Variations should be gradual to avoid stress concentration.

Incorporate Draft Angles

Add a slight taper (typically 1–3°) to vertical surfaces to facilitate easy removal from the mold. This prevents damage to the part or mold during ejection.

Use Fillets and Radii

Replace sharp corners with rounded edges to minimize stress concentrations, improve mold filling, and enhance structural integrity. Fillets also reduce cracking during solidification.

Avoid Undercuts

Eliminate features that require complex cores or side-action molds, which increase cost and production time. Simplify geometry to align with straightforward mold separation.

Optimize for Metal Flow and Solidification

Design features (e.g., ribs, gussets) to guide molten metal flow and ensure directional solidification. Place critical sections away from gates to minimize turbulence and defects like cold shuts.

Select the Right Casting Material

Choose alloys with suitable fluidity, shrinkage rates, and thermal properties for your application. Consider cost, corrosion resistance, and post-casting processes (e.g., machining, heat treatment).

Simplify the Design

Reduce unnecessary complexity by merging features, minimizing cores, and avoiding intricate geometries. Strive for functional simplicity to lower tooling costs and improve yield.

Define Realistic Tolerances and Surface Finishes

Avoid over-specifying tolerances or surface quality, as tighter requirements increase machining and inspection costs. Collaborate with foundries to align design with process capabilities.

Bonus Consideration: Early Collaboration with Foundries

Engage with manufacturing experts during the design phase to address potential issues (e.g., parting line placement, thermal management) and leverage their insights for optimal casting outcomes.

By integrating these principles, you can enhance part quality, reduce production costs, and streamline the casting process.