The specific composition can vary slightly depending on the intended application, but the main components are always these four metals.

Here's a typical breakdown:

* Aluminum: The primary component, usually around 93-95%

* Copper: The second largest component, typically 4-5%

* Magnesium: Typically 0.5-1%

* Manganese: Usually around 0.5%

Duralumin is known for its strength and light weight, making it a popular choice for aircraft construction.