Aluminium extrusion: how it works, costs and design rules

Heated aluminium billets are pressed through a shaped die to make long profiles with a constant cross section: heat sinks, frames, rails and enclosures.

Typical tolerance

EN 755-9, roughly ±0.15–0.3 mm on small profiles

Quantities

Hundreds of kilograms and up

Lead time

4–8 weeks for a new die

Materials

6060, 6063, 6082 aluminium

How it works

A billet at about 450–500 °C is pushed through a steel die. The profile is cooled, stretched straight, cut to length and aged to its final temper (usually 6060-T6 or 6063-T6).

Benefits

• Low die cost compared with casting or moulding.
• Complex cross sections in one piece.
• Very cheap per metre at volume.

Limitations

• Constant cross section only.
• Minimum order quantities by weight.
• Machining needed for holes and cut-outs.

What drives the cost

• Die complexity (hollow profiles cost more).
• Weight per metre.
• Cutting and machining to length.

Design rules

• Keep wall thicknesses as even as possible.
• Round off sharp corners.
• Prefer 6060 or 6063 for complex shapes; 6082 for strength.

Preparing your STEP file

• Send a DXF of the cross section and a STEP of the machined length.
• Mark extruded faces versus machined faces on the drawing.

See also the full STEP export checklist and the comparison of all processes.