I have a question isn't all aluminum cast at some point? Think about it, at the aluminum factory they take the aluminum melt it down and cast big blocks for the industry. The different grades are different alloys they add to the aluminum. I don't know a lot but I seen this show called Modern marvels and it was on how aluminum is made. I think Integy is a really low grade aluminum http://www.google.com/url?sa=t&ct=re...swrOjnfm7ll9Qw

I hope this link works it is very informative