Dear Etch,
The source for this alloy spec is EN 1706 year 1998 which replaces the previous DIN1725 for the material specification for Aluminium alloys.
The Numerical designation for the alloy in EN AC 47000.
The spec is Si 10.5-13.5%
Fe0.8(0.7)
Cu1.0(0.9)
Mn 0.05-0.55
Mg0.35
Cr0.1
Ni0.3
Zn0.55
Pb0.2
Sn0.1
others 0.05 each
others 0.15 total(Figures in bracket indicate percentages in ingot )
This is an alloy equivalent to LM6 and is the alloy nearest to eutectic temp around 576C.Can be used where pressure tightness is required.
Hope the information is enough.