'Iron' in the Bible

After they passed the first and second guard posts, they came to the iron gate that leads into the city, which opened to them by itself. They went outside and passed one street, and immediately the angel left him.

and he will shepherd them with an iron scepter;he will shatter them like pottery—just as I have received this from My Father.

they had chests like iron breastplates; the sound of their wings was like the sound of chariots with many horses rushing into battle;

But she gave birth to a Son—a male who is going to shepherd all nations with an iron scepter—and her child was caught up to God and to His throne.

merchandise of gold, silver, precious stones, and pearls; fine fabrics of linen, purple, silk, and scarlet; all kinds of fragrant wood products; objects of ivory; objects of expensive wood, brass, iron, and marble;

A sharp sword came from His mouth, so that He might strike the nations with it. He will shepherd them with an iron scepter. He will also trample the winepress of the fierce anger of God, the Almighty.