Steel

Steel is a metal alloy of primarily Iron and Coal that is stronger and more flexible than iron. Due to the abundance of iron and coal in Azeroth, those who have discovered the means of making steel have employed its use in nearly every aspect of their lives.

Balance of Coal
As early metallurgists in Azeroth must have discovered, the balance of iron and coal content when smelting steel is very important. Using too little coal yields an end result soft and weak like iron, but using too much coal yields a brittle metal known as "Pig Iron."

Uses
As mentioned, Steel can be employed in a wide range of uses due to its strength and flexibility. Originally used in crafting tools and implements, it was quickly adapted for armor and weaponry. As the production of steel grew in Azeroth, the alloy was applied to everyday life - including dining ware, toys and building construction. The armies of Azeroth continue to employ steel as a primary material in their constructs of war, plating their ships and equipping their soldiers with steel.