Limits of the evidence for Korea's iron industry

What is known about Korea's iron and steel industry and the metals used for cannon?

The iron industry appears advanced, but the available discussion is too uneven to give a precise regional or material breakdown.

Korean ironworking appears advanced in broad terms, but the discussion does not support a confident account of exact production or the balance among iron, steel, and brass. Capability also varied by place, and weak royal leadership complicated how effectively technical capacity translated into military power.