At the end of last season, the GDC answer asked for a specific example of "extruded aluminum," such as this one: 8020.net/1010.html
T-slotted aluminum is available for many suppliers (80/20 is probably the most well known), and comes in a variety of sizes. Will these be legal in accordance with VUR4 section a, "Standard raw material finishing processes, such as extrusion. heat treating..."?