'Iron' in the Bible

Thou shalt break them with a rod of iron; thou shalt dash them in pieces like a potter's vessel.

Whose feet they hurt with fetters: he was laid in iron:

Such as sit in darkness and in the shadow of death, being bound in affliction and iron;

For he hath broken the gates of brass, and cut the bars of iron in sunder.

To bind their kings with chains, and their nobles with fetters of iron;