Swedish ore accounted for roughly 43 percent of Germany's iron-ore supply and was unusually pure. German mills designed around that feedstock would need more energy and additional work to use lower-quality substitutes, while receiving less ore overall. In some armament uses the Swedish share was substantially higher, magnifying the effect on specialized steel. The loss affects armour plate, gun barrels, submarines, tanks, and other products dependent on high-quality steel because the ore is not readily interchangeable.
Notable Point · 35:45-38:25
Why Swedish ore matters more than a lost cargo route
High-purity Swedish ore supports German steelmaking; losing it creates both a quantity shortage and an industrial conversion problem.