Abstract: In continuous casting of aluminum base alloy in sheet form where the alloy comprises small but effective amounts of silicon, iron, manganese, magnesium and copper, an objectionable amount of edge cracking has occurred in the product. This has necessitated side trimming the sheet with the resultant cost of the edge shearing operation and wasted energy in melting the scrap. Applicants have discovered that by increasing the iron and manganese contents of the alloy and decreasing the silicon and magnesium contents, edge cracking can be eliminated or reduced to the point where edge shearing can be eliminated or significantly reduced.