1. Iron
1.1. Sweden
1.1.1. Iron was a primary source for creating steel, which was used in making many weapons, such as tanks, ships, and firearms.
2. Tungsten
2.1. Spain & Portugal
2.1.1. Tungsten strengthened steel, so that guns could be fired without worrying about the barrels being damaged by excessive heat.
3. Cobalt
3.1. Turkey & Russia
3.1.1. Cobalt was another ingredient in making military grade steel. It was also used in making high-impact tools for manufacturing.
4. Copper
4.1. Britain, Russia, &Yugoslavia
4.1.1. Copper was used for electrical wiring, because of its electrical conductivity.
5. Aluminum/Boxite
5.1. Hungary & Yugoslavia
5.1.1. Aluminum and Boxite were used in making everything from military vehicles, to pipes, to buildings.
6. Nickel
6.1. Russia
6.1.1. Nickel was used to strengthen metals and reduce oxidation (rust).
7. Phosphates
7.1. North Africa & Russia
7.1.1. Phosphates had many uses, including manufacturing and agriculture.
8. Tin
8.1. Britain & Russia
8.1.1. Tin saw use in producing metals, as well as being used for food storage.
9. Uranium
9.1. Belgium
9.1.1. The NAZI's were using Uranium in experiments to create new power sources. While they knew it could be used to create a powerful weapon as well, that was not their primary focus.