Wall thickness is one of the most crucial design parameters in aluminium die casting.
It directly affects part strength, cooling behavior, material usage, and overall production cost.
Getting it right helps reduce defects, avoid unnecessary machining, and ensure the finished part performs as intended.
So, what’s the ideal range?
For most aluminium die cast parts, the minimum wall thickness starts at 0.5 mm (0.020 in), while maximum thickness can reach up to 15 mm (0.60 in) depending on the size and complexity of the part.
Maintaining consistent wall thickness across the design is equally critical for quality and manufacturability.
Now, this guide walks you through the practical wall thickness ranges, design considerations, and expert tips to help you produce stronger, more efficient die-cast components.
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Table Of Contents
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1. What Is the Minimum and Maximum Wall Thickness for Aluminium Die Casting?
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2. Why Wall Thickness Matters and How It Affects Design?
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3. Recommended Wall Thickness Ranges for Aluminium Die Casting
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4. Key Factors Influencing Wall Thickness
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5. What Are the Consequences of Poor Wall Thickness Design?
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6. Design Tips to Optimize Wall Thickness in Die Casting
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7. Summary
Why Wall Thickness Matters and How It Affects Design?
Wall thickness influences almost every stage of the die casting process—from mold filling to part performance. Here’s how:
• Metal flow: If walls are too thin, molten metal may solidify before completely filling the mold, leading to incomplete parts. If too thick, the metal slows down, increasing the risk of trapped gases and cold shuts.
• Cooling and solidification: Thinner walls cool quickly and evenly. Uneven or thicker sections cool at different rates, which can introduce internal stresses, shrinkage cavities, and surface defects.
• Mechanical strength: Thin or uneven sections may become weak points that reduce a part’s load-bearing capacity or make it prone to failure.
• Production cost: Thicker parts require more material and longer cycle times, increasing cost and energy consumption.
Managing wall thickness isn’t just about following best practices—it’s about building a reliable, manufacturable product.
Recommended Wall Thickness Ranges for Aluminium Die Casting
The right wall thickness depends on your part’s size, geometry, and function. Here are general guidelines based on industry norms:
• Small parts: ≈ 0.5 mm (0.020 in)
• Medium parts: ≈ 1.0 mm (0.040 in)
• Large parts: ≈ 1.5 mm (0.060 in)
• Maximum thickness range: Up to 15 mm (0.60 in) for large, structural parts
These ranges provide a balance between ease of casting, structural integrity, and cost-efficiency.
Can You Go Below 0.5 mm?
Yes—but only under specific conditions.
With high-pressure systems, optimized die design, and tight process control, some manufacturers can achieve ultra-thin walls down to 0.3 mm (0.012 in).
These are typically used in:
• Electronic housings
• Automotive lightweight components
• Aerospace parts with strict weight limits
However, such thin-walled designs demand advanced tools and may not be practical for general-purpose castings.
How Thick Is Too Thick?
Walls thicker than 5–15 mm, depending on part size, can significantly slow down cooling and increase internal porosity or shrinkage issues.
If thicker sections are unavoidable, incorporate ribs or cores to distribute material more effectively and avoid over-massive zones.
Key Factors Influencing Wall Thickness
Several interconnected factors influence how thin or thick your part walls should be:
1. Part Size and Complexity
• Smaller parts can typically support thinner walls due to shorter flow paths and simpler shapes.
• Larger or complex parts often require thicker walls to fill the mold reliably and resist warping from long cooling cycles.
2. Material Selection (Alloy Type)
• Al-Si alloys (e.g., A380) are commonly used in die casting and have good fluidity, allowing thinner sections.
• Al-Cu alloys may require thicker sections due to lower fluidity and longer solidification times.
3. Process and Tooling Capabilities
• High injection pressures, proper venting, and precise mold temperature control enable better fill and cooling, allowing thinner designs.
• Low-end or outdated equipment may limit how thin you can go without sacrificing quality.
4. Cooling and Heat Dissipation Needs
• Thin walls cool faster, which can speed up production but may lead to defects if cooling is not well controlled.
• Thick walls may cause thermal gradients, which increase the risk of internal stresses or dimensional distortion.
5. Mechanical Load Requirements
• If the part needs to endure vibration, torque, or pressure, you may need thicker sections—or compensate using ribs or support structures.
Ultimately, wall thickness is not a standalone metric—it’s a function of alloy, geometry, process, and performance expectations.
What Are the Consequences of Poor Wall Thickness Design?
Ignoring wall thickness guidelines can lead to serious quality issues. Common problems include:
• Porosity: Trapped air from poor metal flow causes voids that weaken the part.
• Shrinkage cavities: Thick zones cool unevenly, leading to internal gaps and weak points.
• Warpage: Uneven cooling creates residual stress, distorting part geometry.
• Dimensional inaccuracy: Non-uniform shrinkage makes it hard to meet tolerance requirements, especially in mating parts.
In many cases, these issues only become apparent during post-casting machining or field use—leading to scrap, returns, or failures.
Design Tips to Optimize Wall Thickness in Die Casting
Here’s how to ensure your design supports both quality and manufacturability:
• Maintain uniform wall thickness wherever possible—this ensures even cooling and solidification.
• Avoid abrupt changes in thickness. Use fillets or gentle transitions between thick and thin areas to minimize stress points.
• Use ribs for strength instead of increasing wall thickness. Ribs improve rigidity without excessive material use or extended cycle times.
• Run casting simulations to predict metal flow and cooling behavior. This helps identify potential issues before tooling investment.
• Collaborate early with your die casting supplier. Foundry teams can provide invaluable input on what’s achievable with their equipment and alloys.
These practices are especially important when working on high-volume, precision-dependent applications.
Conclusion
Wall thickness in aluminium die casting is far more than a basic dimension—it’s a performance driver.
The ideal minimum starts at 0.5 mm, though specialized applications can reach 0.3 mm.
On the other end, maximum wall thicknesses typically range up to 15 mm depending on size and structural requirements.
But the key isn’t just staying within limits—it’s about designing for uniformity, manufacturability, and mechanical needs.
Successful aluminium die casting starts with careful wall thickness planning and a clear understanding of how material, tooling, and geometry interact.
With thoughtful design and early collaboration between engineers and suppliers, you can achieve stronger, lighter, and more cost-effective components—ready to perform in any industry.
