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Differences Between Cast Aluminum & Extruded Aluminum

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Aluminum is a versatile metal perfect for various manufacturing methods, including casting and extrusion. Aluminum is easy to work with, and manufacturers can create products through casting, machining, extrusion, and forging. However, this article focuses more on the cast and extruded aluminum.


If you are on this page, you are probably wondering what the differences between aluminum extrusion and casting are. Let’s dive in and learn more about aluminum extrusion & casting. Know the differences between the two, their properties, and which of the two is perfect for your project. Read on and find out more.



What is cast Aluminum?

Aluminum casting involves heating aluminum metal and pouring liquid aluminum into a mold. This process produces aluminum castings or aluminum casting parts with defined shapes and sizes. Aluminum casting produces metal parts that are highly tolerant, complex, and of high quality.


Common casting methods include sand casting, permanent mold casting, die casting, and investment casting. The type of mold used dictates the type of casting process used. We can design molds from steel (a permanent solution) or design them from non-metallic materials.


The casting process is much slower; plus, various imperfections could be present in the cast parts. Additionally, aluminum casting involves a secondary process, i.e., fettling. This process helps remove various imperfections through grinding, sanding, or cutting.


Regardless, casting has various advantages in the manufacturing industry. Aluminum casting is quite common for manufacturing products like small appliance components, cookware, and decorative parts. The automotive industry is the largest and most common market for aluminum casting since more than half of the aluminum products used in cars are made through casting.


Various advantages of Aluminum casting include:

· Consistently holds close tolerance

· Has excellent dimensional accuracy

· Creates intricate and complex shapes

· Can make near-net-shape parts

· Can cast complex shapes with thin walls

· Can withstand high operating temperatures


What is extruded Aluminum?

Aluminum extrusion involves using high pressure to force aluminum metal through a metal die. This creates extruded aluminum profiles or shapes. Manufacturers place a heated aluminum billet in a container or cylinder and force it with a ram through the container under pressures of 100000 psi. This amount of pressure affects the final aluminum product.


The other end of the container has a die stack that maintains the die’s opening. The material is cooled by quenching after extrusion and stretched to specific straightness. The manufacturers check the material and age it to the required tempering state.


Aluminum extrusions are more economical, especially when buyers require complex cross-sections made. We can design various shapes and features through the process, including press & snap, flanges, tongue & groove, hinges, sliding fits, etc. Extruded products include window frames, door frames, manifolds, heat sinks, etc.


Advantages of using the aluminum extrusion process include:

· Flexibility of operation

· Conformity to tight tolerances

· Affordable and cost-effective

· High strength-to-weight ratio

· Lightweight

· Wide product range

· Attractive surface finish

· Improved mechanical and structure properties

· Low equipment investment

· Simple process


Differences between extruded  and cast aluminum

Generally, we make cast aluminum from pot metal, a mixture of different aluminum grades that aren’t properly separated or sorted. Often, contractors use cast aluminum for low-grade applications.


Extruded aluminum is stronger and used for high-load applications. Often, we use it to make electronics, automotive, telecommunications, solar energy, and various industries. So, what are the differences between aluminum casting and extrusion?


Manufactured profiles

Aluminum casting helps make complex shapes compared to extrusions since the process is infinitely easier. Aluminum extrusions make a wide variety of specific shapes, with the only condition being that it requires the shapes to have a consistent cross-section.


Size of products

Aluminum casting can make larger products than those made from extrusions since the process is less complicated and requires fewer steps. Aluminum extrusion products are limited by size since the process is more complicated, and the product design is limited to the aluminum billet used.



Aluminum casting creates products that aren’t as strong as those made from aluminum extrusion. The products also have an increased chance of porosity when air gets trapped in the mold. Aluminum extrusions are stronger since the process involves high pressures that strengthen the product.


Products made from aluminum casting have a rougher surface and can show various imperfections like seams. Since we make them under high pressure, aluminum extrusion products have a shinier finish and smoother surfaces.



Aluminum casting molds require lots of time to make and are costly. They aren’t long-lasting as extrusion dies. Inversely, extrusion dies are cheaper, and we can easily make new profiles. This affects the entire manufacturing process.



The Aluminum extrusion process is highly adaptable and requires little effort to make changes. As such, we can change the profiles within a small timeframe than aluminum molds. The aluminum casting process is less adaptable, costly, time-consuming, and takes several weeks for manufacturers to make new die molds.



Die casting is more expensive than aluminum extrusion. Manufacturers use the process in high production runs designed to offset initial costs. The Aluminum extrusion process is cheaper and has a low setup cost that suits it for short production runs.



As mentioned earlier, aluminum extrusion and casting processes make varying products that meet varying demands. Often, aluminum extrusion processes make unique products designed to perform specific functions effectively.


One can argue that products made through this process are designed for durability and reliability. Products made from aluminum casting are still vital to the industry; however, they are replaceable and less durable.

Conclusion- Extruded and cast aluminum

Aluminum extrusion and casting processes are perfect for making aluminum products; however, they serve varying purposes. For instance, products made through casting are not the most durable or have high tensile strength. However, we can make them in large numbers to serve various purposes and recoup their initial cost of production.


Aluminum extrusions are limited because of shape possibilities and could require post-forming machining and assembly. They are stronger, more durable, and less expensive to produce. Choose between aluminum casting and extrusions depending on the need.