'Iron' in the Bible

As one of them was cutting down a tree, the iron ax head fell into the water, and he cried out, “Oh, my master, it was borrowed!”

And the man of God said, Where fell it? And he shewed him the place. And he cut down a stick, and cast it in thither; and the iron did swim.

And they put the sons of Zedekiah to death before his eyes, and then they put out his eyes, and chaining him with iron bands, took him to Babylon.