How do you work out the complexity of an extruded profile?

When we say “complex profiles” will usually cost more, what does that mean? Well, “complexity” in terms of extrusions usually hinges on what’s known as the shape factor. An extruded profile’s shape factor is the amount of surface area that’s generated per unit mass of extrusion.

And the reason complex profiles cost more is that the shape factor affects the cost of tooling (creating a die) and the rate of production. Extruding a perfectly circular cross section, for example, needs the least force, whereas a more complex shape needs more.