There is an indepth thread on the subject
here
Excellence article on Fuchs, (issue#93 pg 107) says the alloy used to make Fuchs is "AlMgSil or AA6082."
AA6082 is; Al 0.9Mg 1.0Si 0.7Mn
--OR--
0.9% Mg (Magnesium)
1.0% Si (Silicon)
0.7% Mn (Maganese)
97.4% Al (Aluminum) [implied balance]
Slightly different from Jacks of Nicks of Joachims factory info.
For yet another data point . . . and a bit more detail;
