Extruded Aluminum pays the most

When I first started scraping aluminum, I quickly learned there are several forms aluminum can come in and the scrap yards pay very different rates for different forms of aluminum.

Just a few of the forms aluminum can come in are:

Cast Aluminum

Ingot Aluminum

Forged Aluminum

Extruded Aluminum

For example the decks of Lawn Boy lawnmowers (the ones that have the funny front wheel set back a bit, they're green) they are made of cast aluminum. So are Toro lawnmowers, cast aluminum.

Cast aluminum is brittle, it'll break if you hit it with a hammer.

Ingot Aluminum, well unless you're a Commercial Forgery that builds Aluminum engine blocks, you're not likely to see much Ingot Aluminum in a dumpster.

What scrap yards pay the most for is Extruded Aluminum

Extrusion is a process used in manufacturing to fabricate parts of uniform cross-sections by squeezing the material through a high-pressure outlet. A die is used to give the desired shape to the extruded metal. While many metals are used for extrusion, aluminum is most widely used for the advantages it offers. Aluminum extrusions form 50% of the total extruded products market

From http://www.zycon.com/Design-Info/Aluminum-Extrusions/Aluminum-Extrusions.asp