Steel

Steel was a type of primitive material used in building. It was noted for not being aesthetically pleasing, and as such was limited to industrial areas. They are composed of Iron and carbon.
Steel was a type of alloy that was used all over the universe. Steel was used to protect the inner components of military towers. It was primitive, crude, and ancient, but it was effective. Ultrasteel, a type of steel, was used for this purpose, as well as many others, such as combat armour.