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Creating Aluminium Dies for Extrusions

What is an aluminium die?

Aluminium dies are designed to allow the extrusion of aluminium billets into complex profiles. They are commonly used in the production of windows, though have usage throughout industry. They consist of a metal disc that has a profile cut into it. It can be any shape that is required, and more complex aluminium extrusions that require hollow sections can be produced with a die that includes a second process plate. The main advantage of aluminium extrusions is that they can be made incredibly strong for very little weight gain. There are three main sections to the production process


In the first instance, an idea is required. It can take the form of a scale drawing or a sketch or even a concept of the extrusions. The design is then re-created using CAD (Computer Aided Design) technology. The CAD image serves a number of purposes:

  • It produces a workable program for the next process
  • Allows for a detailed analysis of the design to check for errors
  • Gives the customer the opportunity to view extrusion in both 2D and 3D, without the expense of tooling and sample production

CAD is a cost effective way of getting what is on paper, ready for the next phase.


The CAD program created to design the extrusion is programmed into a CNC system to produce a template for the task. The main advantages to this process are accuracy and repetition. A CNC is a computer and can create incredibly intricate detail, plus it allows for adjustment should the die cut be incorrect. Secondly, a die has a given life span which varies dependent upon its construction, so once the program is set and approved, it can be replicated at any time.


Aluminium dies are generally constructed of H13 steel which has high hardenability qualities and excellent shock resistance when employed in a hot environment. The die goes through a Nitride hardening process before being employed in production, but first; an aluminium extrusion test is carried out to ensure that the product is of the correct dimensions, is structurally rigid and fit for purpose. Once these facts have been established, the aluminium die is ready for use.

Extrusions have found usage throughout industry due to their flexibility and comparatively cheap production process. A single die is capable of producing several tonnes of highly accurate extrusion.

Further processes

Once the extrusion has been produced, there are many other processes that can be applied, dependent on its purpose. These include anodising and powder coating. Both processes are designed to make the extrusion weatherproof and can be applied in a wide variety of colours and finishes.

Extrusions made from aluminium, using this process, have revolutionised the way lightweight structures and components are designed. New technology and innovations will only increase their versatility

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