'Iron' in the Bible

The house, when it was in building, was built of stone prepared at the quarry; and there was neither hammer nor axe nor any tool of iron heard in the house, while it was in building.

(for they are your people, and your inheritance, which you brought forth out of Egypt, from the midst of the furnace of iron);

Zedekiah the son of Chenaanah made him horns of iron, and said, "Thus says Yahweh, 'With these you shall push the Syrians, until they are consumed.'"