This article explores the standard wall thickness ranges in gravity die casting, the importance of maintaining uniform wall thickness, design strategies to optimize it, and key considerations in thin-walled casting. Please read on to learn how to improve the quality of aluminum alloy die casting products by optimizing wall thickness.
Common Wall Thickness Range
Minimum Wall Thickness
The minimum wall thickness of die casting products depends on several key factors, including part size, structural complexity, the fluidity of the aluminum alloy, and the injection capability of the die casting company’s equipment.
For Small Parts (0.5–0.8 mm): For smaller components, the flow path is short and the filling resistance is low, so the minimum wall thickness can be reduced to 0.5–0.8 mm to ensure smooth and complete cavity filling.
For Medium Parts (1.0–1.8 mm): Medium-sized parts require slightly thicker minimum walls, typically between 1.0–1.8 mm, to support moderate flow distance and more complex structures.
For Large Parts (2.0–2.5 mm): The larger the part, the longer the flow channel, and the higher the requirement for filling capacity, so the minimum wall thickness needs to be appropriately increased to ensure that the metal can be smoothly filled into each area.
Maximum Wall Thickness
While the recommended maximum wall thickness is typically around 5–6 mm, some special applications may require thicknesses up to 15–25 mm.
However, such cases are rare and not generally encouraged. Excessive wall thickness can result in several problems:
More Internal Pores: Thick sections cool more slowly, which can trap gases inside the casting. These gases may form pores, weakening the part.
Shrinkage Issues: Uneven cooling in thick areas can create inconsistencies in shrinkage, leading to surface collapse, internal voids, or cracks.
Higher Residual Stress: Large differences in cooling rates across the casting generate internal stress, increasing the risk of deformation or cracks over time.
A practical guideline is to ensure the thickest section is no more than twice the thickness of the thinnest section.
This promotes thermal balance and minimizes internal stress and structural problems.
Wall Thickness Range Supported by CEX Casting
CEX Casting supports a stable wall thickness range from 2 mm to 15 mm.
This allows us to handle a wide variety of applications, from intricate thin-walled designs to large-scale thick-walled components.
Our Advantages
Proprietary Casting Technology: Our patented techniques in feeding, venting, and cooling dramatically improve the filling performance in thin-walled areas and significantly reduce porosity.
In-House Mold Capabilities: Our dedicated mold workshop handles everything from design to fabrication.
We conduct mold flow analysis to optimize wall thickness distribution before production, helping eliminate casting defects at the source.
Why Uniform Wall Thickness Matters
Improved Flow Dynamics
When wall thickness is uniform, molten metal experiences consistent resistance as it fills the die casting mold.
This reduces flow turbulence, prevents cold shuts, and ensures complete cavity filling.
Even Solidification
With consistent wall thickness, different areas of the casting cool and solidify at nearly the same rate.
This minimizes surface sinks, voids, and internal inconsistencies caused by uneven cooling.
Fewer Defects
Uneven thickness creates stress hotspots that are prone to cracks, pores, and shrinkage. Uniformity helps avoid these problems, improving the overall yield.
Greater Structural Stability
Consistent wall sections enhance dimensional control, reduce thermal deformation, and improve part strength, durability, and performance under operational stress.
Strategies for Optimizing Wall Thickness
Fillet and Chamfer Transitions
In the thick-thin junction area, sharp angle design should be avoided.
It is recommended to use a 1–3 mm fillet or chamfer treatment to achieve a smoother structural transition. This design method can:
Enhance Flow: Rounded transitions reduce resistance, helping molten metal flow smoothly around corners and eliminating cold shut issues.
Minimize Stress: Sharp corners act as stress concentrators. Fillets help distribute stress more evenly and reduce the chance of cracking.
Improve Cooling Uniformity: Rounded edges avoid heat buildup in corners, allowing more consistent cooling and reducing the chance of shrinkage and dents.
Apply Appropriate Draft Angles
Draft angles make it easier to remove castings from the mold. In thin-walled areas, precise control of draft angle is essential.
A draft of 0.5°–1.0° is recommended to avoid sticking, surface damage, or part deformation during demolding.
Use Reinforcing Ribs
In areas where structural strength needs to be improved, it is not recommended to simply thicken the wall, but to give priority to adding reinforcing rib structures.
This design approach has the following advantages:
Reduce Weight: Ribs increase structural integrity without significantly increasing material usage, helping to keep components lightweight.
Accelerate Cooling: Thin-walled structures with ribs cool faster and more evenly, reducing internal stress.
Prevent Defects: Ribs promote smoother metal flow and reduce the chance of porosity, shrinkage, and loosening that typically occur in overly thick sections.
The thickness of reinforcing ribs should be about 2/3 to 3/4 of the adjacent wall to avoid issues like shrink marks or stress accumulation caused by ribs that are too thick.
Key Considerations for Thin-Walled Die Castings
Though thin-walled die castings have advantages such as light weight and high precision, they also bring higher design and process challenges.
Special attention should be paid to the following points during the design and production process:
Maintain Uniform Thickness: Avoid local thickening in thin-walled areas. Uneven thickness may lead to incomplete filling or cold shuts.
Use ribs or rounded corner transitions to strengthen the structure.
Matching Temperature and Speed: The molten aluminum temperature and injection speed need to be coordinated and controlled.
Too low is prone to short pouring, and too high is prone to mold damage. It needs to be repeatedly verified through trial molds.
Ensure Effective Venting: Thin walls fill quickly, increasing the risk of gas entrapment.
Molds must include proper venting channels and undergo regular cleaning to maintain gas escape efficiency.
CEX Casting’s Thin-Walled Die Casting Solutions
Tailored Mold Design: For thin-walled components, we optimize gating, venting grooves, and cooling channel layouts to ensure fast and even metal flow during injection.
High-Speed Die Casting Equipment: Our machines are equipped with high-response injection systems designed specifically for thin-walled production, ensuring full cavity filling and reduced porosity or distortion.
Strict Quality Control: Thin-walled castings are more prone to hidden defects.
We perform X-ray inspections and mechanical testing during production to catch issues early.
Full inspections are also available upon request based on customer needs.
Conclusion
Wall thickness plays a pivotal role in aluminum alloy die casting. It determines how the part fills, solidifies, and performs in service.
By optimizing wall thickness, manufacturers can reduce defects, enhance structural reliability, and increase overall production efficiency.
As a leading aluminum die casting manufacturer, we offer complete support for wall thickness optimization, from mold design to final inspection.
With patented technologies and in-house expertise, we ensure every product meets customers’ standards.
Contact us now for a free quote and see how we turn your next aluminium die casting project into reality.