Twmaster,
Stay away from the "T" aluminums. The 50 series, with 0 temper would work best. The 6061 and 6063 are great for Machining, but will not bend well. The 5052 does not machine as well but will bend just fine. The Alloy 3003 is litterally a "Pure Commercial" grade aluminum but not hold up well "strength" but be "bendable".
My recommendation would be to look for the 5052 in the size your looking for, all in all it will work best. Brass could be another avenue to look into.
Good Luck, let me know if you want more info and I will be happy to help!
Glen |