During the designing process of an aluminum part, it is crucial to consider the manufacturing process that you will be using to manufacture it. There are various options for producing aluminum, and one of the most preferred methods for designers is aluminum die casting.

For most industrial, automotive, and telecommunications products, aluminum die casting is the ideal method. This method is also commonly used for forming lighting, hydraulic, and electrical components.

If you want to learn more about the aluminum die casting process and need help in determining if this is the right option for your component, then you are in the right place. The following are 5 important things you need to know about aluminum die casting.

What is the Aluminum Die Casting Process?

Aluminum die casting is a process wherein complex aluminum components can be formed using aluminum. First, the aluminum alloy will be heated at high temperature levels until they are completely molten.

The liquefied aluminum will be injected into the cavity of the steel die using high pressure. The die is composed of two halves. Once the molten aluminum has solidified, they will be separated so that the cast aluminum part will be exposed.

The resulting aluminum product is accurately created with a smooth surface and often requires less or no machining at all. By using steel dies, you will be able to repeat the process as much as you want using the same mold until it deteriorates. Hence, the aluminum die casting process would be perfect if you are producing high-volume aluminum parts.

The Benefits of Aluminum Die Casting

Compared to other metal-forming processes, the die casting aluminum process has many benefits, making it an ideal option for producing aluminum parts. One of the most remarkable is its capability of creating complex shapes that cannot be effectively accomplished by either machining or extrusion.

A good example would be the creation of intricate automotive parts, such as engine blocks and transmissions. Unfortunately, other metal-forming processes are not capable of achieving the tight tolerance and complexity required for these specific products.

Other benefits include its capability of accommodating both small and large parts and achieving smooth or textured surfaces. The following are some of the advantages that the die casting process offers:

Strong and Lightweight

Parts made from aluminum alloys through the die casting process are guaranteed to have superior strength-to-weight ratios, making them perfect for applications that require excellent strength and lightness. This is the reason why die-cast aluminum parts are popularly used in various industries, including aerospace, automotive, and electronics.

Highly Efficient

The aluminum die casting process has the capacity to produce complex shapes with consistency and high precision. This process allows the production of thin walls and intricate details which can be costly or difficult to accomplish using other manufacturing methods.


Due to its high efficiency, the aluminum die casting process is capable of producing high volumes at low costs. The rapid cycle times and the reuse of molds can greatly contribute to the cost-effectiveness in huge scale production.

Smooth Surface Finish

You can guarantee that the parts produced from the die casting process have fine details and smooth surfaces, reducing the requirement for any additional surface finishing processes.


With the aluminum die casting process, you will be able to produce parts with different complexities and sizes, from small intricate parts to larger structural components.

Aluminum die casting parts can be used in different applications in various industries, such as in telecommunications, appliances, electronics, aerospace, and automotive. It is an efficient and cost-effective way of producing lightweight, high-quality, and complicated parts with an excellent surface finish and highly accurate dimensions.

Important Considerations During Part Design

When designing the component for aluminum casting, there are certain things that should be considered. First, the cavity or mold should be designed in such a way that it can be separated, allowing for the easy removal of the hardened aluminum part.

The line where the two halves of the cavity will be separated is known as the parting line, and this is something that should be considered during the early part of the die design.

Another crucial factor to consider is the placement of the injection points. You can design the die in such a way that there are a lot of injection points, especially when the molten metal will quickly solidify before it reaches all the crevices in the die. This is also valuable if the cavity is included in the design. You can put aluminum around it, yet the component can still be taken out once the mold has been separated.

The thickness of the walls is also something that should be considered. Typically, there are no specific guidelines when it comes to the minimum wall thickness; however, it is recommended that there should be a consistent thickness on the walls.

Aluminum Die Casting Vs Green Sand and Permanent Mold Casting

Two of the most popular alternatives for the aluminum die-casting process are green sand and permanent mold casting. In green sand processes, wet sand is used for forming the mold for the cast. That is why this is less expensive compared to the other two processes.

In the die-casting process, molten aluminum is injected into the mold; however, in permanent mold castings, the molten aluminum is poured into the mold using gravity. It is also possible that permanent mold castings can create stronger casts.

However, when it comes to smooth surfaces and tolerances, permanent mold casting is much better compared to the other two methods. Most often, it does not even require further surface treatment.

Machining and Finishing

Ultimately, die-cast aluminum components only need minimal machining, and there are various options for surface finishing. Die-casting parts already have an excellent surface finish.

However, they still have some imperfections, for instance, the metal seams on the halves where the mold is joined. Rough surfaces or any other imperfections on the components can be addressed by several methods such as sanding, orbital sanding, or sandblasting.

To enhance fatigue resistance on die-cast aluminum, the cold process of shot peening can be used. Another alternative would be a decorative or a protective coating, such as a powder coat, can be applied to the finished part. Aside from this, there are also other kinds of modifications that can be used on the parts after casting, for instance, drill tapping.

Common Aluminum Die Casting Alloys

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There are several types of aluminum alloys that can be used for die casting, and some of the common ones are A380, 383, A413, B390, CC401, and A360. Keep in mind that the most important thing to consider when selecting an appropriate alloy is your predetermined application.

For instance, A360 has superior pressure tightness, excellent corrosion resistance, and exceptional fluidity when molten. Among the cast alloys, B390 has the lowest ductility while having high hardness and excellent wear resistance. That is why it is commonly used for significant applications such as automotive engine blocks.

On the other hand, Alloy A380 seems to be the jack-of-all-trades since it has an excellent combination of casting and product properties. Additionally, it is also the most popularly chosen alloy for casting a wide range of products.


Ultimately, your choice for metal-forming process will greatly depend on your budget, the quantity of the parts that you want to produce, as well as the intended application of your aluminum part. Die casting can be costly, however, it is definitely a worthwhile method, especially if you are trying to produce high volume of parts and designs that have high complexity.

SEI Castings offer professional aluminum die casting services. Whether it is a custom or a standard part, we can guarantee its quality and precision. Whether you require a highly complicated part or a high volume part, you can email us at sales@seimw.com.