Could you supply more information about the designation? 319-T51 would refer to a permanent mold 319 alloy casting that is artificially aged (i.e. no solution treatment). But the SR prefix is one that is not known to me.
Thanks Swall! You're correct in that it is a permanent mold Aluminum casting. The SR prefix is something I could find only in a brochure of Harmony Castings.
The "SR" could indicate a strontium modified casting. Addition of small amounts of strontium causes the hypoeutectic silicon particles to become much finer than in a non-modified casting and this will increase mechanical properties somewhat.