Design Considerations for Aluminum Die Casting

Aluminum die casting is a popular aluminum casting manufacturing process used to produce complex parts with high precision and consistent quality. It involves injecting molten aluminum into a mold under high pressure and then cooling and solidifying the material to form the desired shape. This process offers many advantages, including excellent dimensional accuracy, high productivity, and the ability to produce intricate geometries. However, to achieve optimal results, it is essential to consider several design factors when creating a die casting.

Design Considerations for Aluminum Die Casting

As a professional aluminum die casting manufactuer, CFS Foundry would like to share some main design considerations for aluminum die casting and provide tips to help you optimize your designs for this process.

Wall Thickness

The first consideration when designing a part for aluminum die casting is wall thickness. The thickness of the walls can significantly impact the part’s quality and performance, as well as the cost of production. Generally, thinner walls lead to faster cooling times, reduced porosity, and better surface finishes. However, it is important to maintain a minimum thickness to ensure that the part is strong and durable enough to withstand the intended use.

For aluminum die casting, a wall thickness of at least 0.5mm is recommended for small to medium-sized parts, while thicker walls can be used for larger parts. Also, it is essential to maintain uniform wall thickness throughout the part to ensure consistent cooling rates and reduce the risk of defects.

Draft Angles

Draft angles refer to the taper applied to the vertical walls of a die casting to enable it to be easily ejected from the mold. This angle is critical to ensure the smooth release of the casting from the mold and to avoid the formation of undercuts or trapped air pockets. The general rule of thumb is to use a draft angle of 1 to 2 degrees for small parts and up to 5 degrees for larger parts.

However, pls note that the draft angle should be balanced with the part’s functional requirements, as too much draft can weaken the part’s structure and affect its performance.

Fillets and Radii

Adding fillets or radii to the corners and edges of a die casting is crucial for several reasons. Firstly, sharp corners can cause stress concentrations, leading to cracking or failure of the part. Secondly, fillets and radii can help to reduce turbulence and improve flow during the injection process, resulting in better surface finishes and reduced porosity.

The recommended fillet radius for aluminum die casting is typically between 1 and 2mm, depending on the part’s size and complexity. However, pls ensure that the fillets are consistent and that there are no sharp edges or corners that could compromise the part’s strength.

Wall Thickness Variations

While uniform wall thickness is recommended for aluminum die casting, it is sometimes necessary to incorporate variations in the thickness to meet specific design requirements. For example, thicker walls may be required in areas of the part that are subject to high stress or load, while thinner walls may be suitable for less critical areas.

When designing wall thickness variations, it is essential to make sure that the transition between thick and thin sections is gradual and that there are no sudden changes that could cause stress concentrations or affect the part’s structural integrity.

Bosses and Ribs

Bosses and ribs are often used in die casting designs to provide additional strength and stiffness to the part. Bosses are raised features used for mounting or attaching the part to other components, while ribs are thin, protruding features that improve rigidity and resistance to bending or twisting.

When designing bosses and ribs, it is necessary to ensure that they are consistent in size and shape and that they do not interfere with the part’s functional requirements or affect the mold’s ejection. Additionally, the designers should maintain proper draft angles and fillets to avoid stress concentrations and improve the part’s overall quality.


Undercuts are features on a die casting that prevent the part from being ejected from the mold in a straight line. These features require complex mold designs and additional mechanisms, such as slides or lifters, to enable the part to be released from the mold. As such, designing parts with undercuts can significantly increase the cost of production.

To reduce the cost and complexity of mold designs, it is recommended to minimize the number of undercuts or eliminate them altogether, if possible. If undercuts are necessary, it is essential to work closely with the mold designer to ensure that the part can be released efficiently and that the overall design is optimized for production.

Surface Finish

The surface finish of a die casting is critical for both aesthetic and functional reasons. A smooth surface can improve the part’s appearance and reduce the risk of corrosion or wear, while a rough surface can affect the part’s performance and reduce its lifespan.

To achieve the desired surface finish, pls consider factors such as the mold material, the injection pressure, and the mold temperature. Additionally, it may be necessary to incorporate features such as ejector pins, vents, or overflow channels to prevent air pockets or other defects that could affect the surface finish.

Material Selection

Aluminum die casting can be performed using a variety of alloys, each with its unique properties and characteristics. The choice of alloy will depend on several factors, including the part’s intended use, the required strength and stiffness, and the desired surface finish.

Some of the most commonly used aluminum alloys for die casting include ADC12, A380, and A413. ADC12 is known for its excellent casting properties, while A380 is popular for its high strength and good corrosion resistance. A413 is preferred for its superior fluidity and ability to fill complex geometries.

It is essential to work closely with a quality aluminum die casting company like CFS, who can help to select the most suitable alloy for your die casting, and to optimize the design for the chosen material.


Aluminum die casting offers many benefits for the production of high-quality parts, but it is crucial to consider several design factors to achieve optimal results.

As an experienced aluminum die casting manufacturer, by working closely with CFS Foundry, designers can optimize their designs for the die casting process and achieve high-quality results at a reasonable cost. With these design considerations in mind, designers can create complex, precise, and reliable parts for a wide range of applications. If you need any help on your design of aluminum die cast parts, pls feel free to contact us!

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