The Process Of Custom Aluminum Extrusions

While the term custom aluminum extrusion may be familiar, the process of extrusion itself is often much less likely to be fully understood. It is a complex process which requires engineering and design understanding combined with the actual equipment and technology to create very specific shapes of aluminum alloy.

A custom aluminum extrusions will have a specific cross-sectional profile. This can be very simple, such as a rectangular, round, or square tube, or it can be a T, I or Z-shaped bar.

In addition, it is possible to create a round or oval shape inside a square or rectangular bar or to create specialized types of trim for boats or trailers, tracks for shutters or awnings.  It is also possible to develop unique cross-sectional profiles which involve multiple shapes for the inside and outside of the custom aluminum extrusions.

The Process

Regardless of the complexity of the shape of the custom aluminum extrusions the process of making the bar is the same. It first starts with an engineer designing the shape of the die, or the form, which will be used to shape the heated aluminum alloy.

A billet, a large piece of aluminum alloy, is heated to the correct temperature, which will range between 800 and 925 degrees Fahrenheit. There a lubricant added to the heated material to prevent it from slowing down or sticking in the die.

This billet is then placed into the extrusion compartment where a block or ram is used to exert pressure on the back to push the heated alloy into the die. At the same time, liquid or gas nitrogen is pumped into the chamber to prevent oxidation.

Pins and special types of piercing materials are used in the form of the die to create the hollow spaces in the final extrusion. As the alloy is pushed through the die, it cools and hardens. It is pushed out the other end of the die in a long, continuous replica of shape.

From here the custom aluminum extrusions is then cut into the desired lengths. The pre-cut pieces are exposed to a specific low heat in an aging oven to increase the strength and to allow the aluminum to develop the protective coating. It is then custom finished if required, which can provide additional hardening for specific uses.

A custom aluminum extrusions can be created for any need from retrofitting something old to creating something completely new. The process, once the die is completed, is relatively fast with many companies offering just a few days for turnover time to have a custom product ready to ship.

Eagle Mouldings has been specializing in custom aluminum extrusion since 1989. To learn more about our services or to see our inventory visit us online at

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