Extrusion: what is it?

The process in a nutshell: Die makers produce a die based on a profile drawing. The die is placed in the extrusion machine. An oven heats a solid rod of aluminum or magnesium to several hundred degrees, softening the material and preparing it for extrusion through the die. This is done under high pressure. On the other side of the die, the aluminum comes out in the shape of the die profile. It is then cooled and, once all the base material has been extruded through the die, straightened. Afterward, it is cut and further treated if necessary.

Watch the animation for more information.