Part of the process & material guide series — see all →
Extrusion turns a custom cross-section into a long, straight, repeatable profile for a fraction of the cost of machining it. The die is cheap; the secondary operations are where the schedule and most cost surprises hide.
If your part is a rail, frame, heat-sink fin, enclosure section or any long constant cross-section, extrusion is almost always the cheapest way to make it. A single die pushes heated aluminum through a shaped orifice, producing meters of identical profile. This guide covers the die, the alloys, and the secondary work that decides whether you receive usable parts or a pile of raw bar.
Unlike machining, where the CNC program is the IP, in extrusion the die is the product. A well-designed die holds tolerance along the length, minimizes twist, and runs for a long life. Design considerations:
Die cost is modest (hundreds to low thousands of dollars) and you should own it. A DFM pass on the cross-section before the die is cut prevents a profile that won't straighten or won't hold dimension.
6063 is the extrusion favorite — excellent surface for anodizing and easy to shape. 6061 is stronger but less "extrudable" and harder to get a cosmetic finish on. Choose by function: decorative or light-structure rails lean 6063; load-bearing members lean 6061. Both should come with a material certificate (mill cert) for traceability.
A raw extrusion is rarely the finished part. It needs cutting to length, CNC machining of ends or holes, possibly bending, then surface finish — anodize or powder. Coordinating these in one chain (die → cut → machine → finish) is what delivers a usable part instead of a pile of raw bar.
This is where multi-process coordination pays off: the extruder, the machining shop and the finisher working to one plan, not three vendors guessing at each other's tolerances.
I design the cross-section for extrudability, own the die on your behalf, and coordinate cutting, machining and finish into one delivery. Send the profile; I'll return the die plan, the process chain and the landed cost.
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Send the profile and target market — I'll plan the die, the process chain and the cost drivers.