'Iron' in the Bible

And [after they] had passed the first and second guard, they came to the iron gate that leads to the city, which opened for them by itself, and they went out [and] went forward [along] one narrow street, and at once the angel departed from him.

and "he will shepherd them with an iron rod; he will break [them] in pieces like jars made of clay,"

and they had breastplates like iron breastplates, and the sound of their wings [was] like the sound of many {horse-drawn chariots} running into battle.

And she gave birth to a son, a male [child], who is going to shepherd all the nations with an iron rod, and her child was snatched away to God and to his throne.

cargo of gold and silver and precious stones and pearls and fine linen and purple cloth and silk and scarlet cloth and all kinds of scented wood and all kinds of ivory goods and all kinds of goods of precious wood and bronze and iron and marble

And out of his mouth came a sharp sword, so that with it he could strike the nations. And he will shepherd them with an iron rod, and he stomps the winepress of the wine of the furious wrath of God, the All-Powerful.