Design for Manufacture FAQ: Expert insights

Designing for die casting requires a careful balance between part functionality, manufacturability and cost efficiency. Questions such as "How thin can the walls be?", "Where should gates be placed?", or "What's the best way to avoid porosity?" are common during product development, and that is where Design for Manufacture (DFM) plays a critical role.

We spoke with Max Gondek, Senior Application Engineer at Dynacast, who holds a Mechanical Engineering degree from Purdue University and has over a decade of die casting experience. Below, Max answers the most frequently asked questions about DFM and how early collaboration with Dynacast can optimise part design, tooling and overall production outcomes.

Why is Design for Manufacture (DFM) important?

Max Gondek: It is crucial to collaborate with a Dynacast engineer as early in the design phase as possible. Even small design adjustments can have a major impact on part quality, tool life and production efficiency.

DFM is not about redesigning your part — it is about refining it. Minor adjustments such as uniform wall thickness, draft angles and feature placement can significantly improve material flow, reduce cycle times and eliminate costly secondary machining.

For example, by optimising metal-saver geometry and increasing wall-thickness uniformity, we have improved casting quality, extended tool life and enhanced overall material flow, resulting in better, more consistent parts.

Does Dynacast have a dedicated team for DFM support?

Max Gondek: Absolutely. DFM is what we do every day. Our engineering teams specialise in analysing casting designs and working closely with customers to make data-driven recommendations.

We review each design based on alloy type, part size, tolerance requirements and quality requirements. Dynacast's global engineering network works together weekly, drawing on expertise from multiple facilities to deliver the best results.

We also use advanced casting simulation software (MAGMA) to model part performance, optimise gating and cooling, and predict potential issues before production begins.

How does DFM help avoid shrinkage porosity?

Max Gondek: One of the biggest challenges in die casting is shrinkage porosity — small voids that form as metal solidifies and contracts. The key to minimising porosity is maintaining uniform wall thickness and removing excess mass wherever possible.

By strategically using metal savers or weight savers, we promote even solidification and better metal flow. This reduces porosity, improves surface integrity and shortens cycle time, allowing more parts to be produced per hour and lowering overall part cost.

In short: uniform walls = uniform cooling = fewer defects.

How does draft affect part design in die casting?

Max Gondek: Once the overall geometry is defined, adding draft (a slight taper on walls) is the next crucial step. Draft allows the part to release cleanly from the die without sticking or causing damage.

Think of old ice-cube trays, where the tapered sides make it easier to remove the cubes. The same principle applies to die casting. Without draft, you risk damaging the die or part during ejection, which can lead to downtime and poor surface finishes.

After adding draft, we typically move on to radii, fillets and rounds for further optimisation.

What are the advantages of fillets and radii in part design?

Max Gondek: Sharp corners are stress concentrators and should always be avoided (except at the parting line). Fillets and radii:

• Improve metal flow and filling consistency
• Reduce stress concentrations
• Prevent cracking during solidification
• Extend tool life and improve part strength

Rounded transitions allow molten metal to flow more smoothly, minimising turbulence and ensuring consistent material distribution across the part.

What if my part keeps failing testing? How can DFM help?

Max Gondek: Definitely — and this is a common scenario. When a part fails finite element analysis (FEA), the instinct is often to make the walls thicker. But thicker does not always mean stronger.

Instead of adding mass, we look for structural reinforcement opportunities: ribs, webs, gussets and optimised load paths. These features increase rigidity without compromising flow or introducing porosity, ensuring that strength and manufacturability work hand in hand.

What is the function of ejector pin bosses?

Max Gondek: Ejector pins physically push the finished casting out of the die after solidification. To prevent damage, parts often include ejector pin bosses — small, reinforced areas where these pins make contact.

Designing suitable ejector pin bosses ensures smooth part ejection, protects delicate features and supports automation during post-processing. We often integrate these directly into structural areas such as ribs or heat-sink fins.

Why are tolerances so important in die casting?

Max Gondek: A flawless CAD model does not guarantee a manufacturable part. Even with the right draft and fillets, tolerances must align with die casting process limits.

We help customers evaluate:

• Parting-line design
• Tooling configuration
• Thermal effects and linear shrinkage
• Dimensional control and repeatability

Die casting inherently offers excellent repeatability and can often eliminate secondary machining — but only when tolerances are properly defined from the outset.

How does material selection affect DFM?

Max Gondek: Material choice is just as critical as geometry. The right alloy affects everything from thermal conductivity and strength-to-weight ratio to surface finish.

Dynacast's Metal Selector Tool helps designers compare alloys such as zinc, aluminium and magnesium based on specific project requirements. It enables real-time evaluation of thermal, mechanical and density properties, helping engineers make informed, data-driven material decisions.

Key takeaways: Why early collaboration with Dynacast matters

• Involve DFM experts early to reduce rework and improve manufacturability
• Focus on uniform wall thickness to minimise defects
• Use draft, fillets and ribs to enhance part strength and tool life
• Define tolerances and material choices based on real-world casting data
• Use simulation tools for optimal design validation

Design for Manufacture is not just an engineering checklist, but a strategic process that drives efficiency, consistency and cost savings throughout the entire production cycle.

Dynacast combines decades of experience, precision engineering and cutting-edge simulation to help customers design parts that are stronger, lighter and easier to produce.

To learn more about our processes and best practices, visit our Dynacast FAQ page for additional insights into die casting design, materials and manufacturing excellence.