AN ALUMINUM CASTING ALLOY HAVING GOOD MECHANICAL PROPERTIES IS PREPARED BY ADDING, TO ALUMINUM, COPPER, MAGNESIUM, AND CADMIUM AND, ADDITIONALLY, IF DESIRED, TITANIUM AND BORON, AND, ADDITIONALLY. IF DESIRED, MANGANESE AND SILVER, SOLUTION-HEAT-TREATING THEREOF AT A TEMPERATURE HIGHER THAN 500*C., AND THEN AGEING THE SOLUTION-HEAT-TREATED ALLOY AT A TEMPERATURE BETWEEN 160*C. AND 190*C. FOR 4 TO 48 HOURS. THE ALLOY IS USEFUL IN VARIOUS TYPES OF MACHINE MEMBERS, AIRCRAFT, ROLLING-STOCK MEMBERS, ARCHITECTURAL MEMBERS, AND OTHER STRUCTURAL APPLIANCES.