Y-alloy contains

• 3.5 to 4.5% copper, 0.4 to 0.7% magnesium, 0.4 to 0.7% manganese and rest aluminium
• 3.5 to 4.5% copper, 1.2 to 1.7% manganese, 1.8 to 2.3% nickel, 0.6% each of silicon, magnesium and iron, and rest aluminium
• 4 to 4.5% magnesium, 3 to 4% copper and rest aluminium
• 5 to 6% tin, 2 to 3% copper and rest aluminium