Guangdong Coyo Precision Machinery Manufacturing Co., Ltd.


Aluminum Injection Molding VS Steel Injection Molding

December 05, 2022


Conventional injection molding relies on steel injection molds to produce a large number of parts. However, steel molding possesses certain limitations. Therefore, there is a need for an alternative process like the aluminum molding process.


Based on different features, there are many differences between aluminum injection mold and steel plastic injection mold. This goes above the materials used in making them (Aluminum and Steel) and is more based more on their features, designs, and applications.


Below are a few significant differences between aluminum mold and steel mold for plastic injection molding.



Steel molds are not flexible as their hardness is due to the heat treatment after the design of vital parts of the mold. However, compared to steel injection molding, aluminum molds come from softer materials.


Its design is such that it allows the creation of its mold parts separately, which allows easier removal to adjust prototypes.

Miniature Valve 15MM Manifold


·Turnaround Time

Aluminum plastic injection molds are manufactured using aluminum material by the CNC machining process. Sometimes manufacturers use Electrical Discharge Machining (EDM) when cavities must have sharp corners. Nevertheless, a typical aluminum cavity is made in about 10-15 days as the process requires only mechanical methods. There is no need for special manufacturing equipment or thermal processing is needed.


Steel injection molds also come from the same process. However, they are expensive and take months to manufacture. This is due to the rigidity and hardness of steel. Due to steel’s hardness, it requires special manufacturing equipment and undergoes thermal processing to increase its mold life.


·Mold Robustness

Mold robustness refers to the number of parts a mold can make before it becomes too corroded or worn out. This factor is hugely dependent on the design and the genetic makeup of the mold.


Steel injection molds are hard since their manufacturing process includes heat treatment. They also possess few joints, which makes them rigid and durable. Thus, steel injection molds can produce millions of parts.


However, aluminum prototype mold come from aluminum which, compared to steel, is a soft material. Therefore, it has lesser mold robustness than steel injection molds. Nevertheless, alloys made from aluminum are strong and can guarantee a batch of up to 5000 parts.


·Production Time

Production time is the time taken from the injection of polymer to the ejection of the final product. It is an essential factor in the batch product manufacturing process and it depends on the material of the mold, temperature, and pressure.


Aluminum injection molds are not strong enough to withstand intense pressure and temperature. Therefore, the production time for aluminum prototype molds is usually within 40 - 70 seconds. However, steel injection molds can withstand high temperatures and pressure better than aluminum molds and require only a few seconds to produce parts.


Guangdong Coyo Precision Machinery Manufacturing Co., Ltd. is a national new technology enterprise specializing in the production of industrial aluminum profiles and extension products, integrating research and development, design, extrusion and processing. If you have any questions, please contact us now!