An alloy containing principally aluminum, approximately 4% copper, 0.2 to 0.75% magnesium, and 0.4 to 1% manganese; individual manufacturers may include small amounts of silicon and iron.
An alloy containing principally aluminum, approximately 4% copper, 0.2 to 0.75% magnesium, and 0.4 to 1% manganese; individual manufacturers may include small amounts of silicon and iron.