Heat Treatable & Non-Heat Treatable Base & Fillers
Aluminum Alloy Designation Tree
The Aluminum Association uses a four digit numbering system for designating wrought aluminum and wrought aluminum alloys.
The image above shows the wrought alloy groups as well as a few examples of common products from each group.
The significance of each number is described below.
1st Digit – Identifies the major alloying element.
2nd Digit – Identifies the rendition of an alloy. For example, 5356 is the 3rd rendition of the original base alloy 5056.
3rd and 4th Digits:
In the 1XXX group, the last two digits indicate the minimum aluminum percentage. For example, alloy 1188
has a minimum purity of 99.88% aluminum. Alloy 1350 has a minimum purity of 99.50% aluminum.
In the 2XXX – 8XXX groups, the last two digits serve merely as counters. For example, 3004 was the next
manganese alloyed chemistry after 3003.