'Iron' in the Bible

And the house, when it was in building, was built of stone made ready before it was brought thither: so that there was neither hammer nor axe nor any tool of iron heard in the house, while it was in building.

For they be thy people, and thine inheritance, which thou broughtest forth out of Egypt, from the midst of the furnace of iron:

And Zedekiah the son of Chenaanah made him horns of iron: and he said, Thus saith the LORD, With these shalt thou push the Syrians, until thou have consumed them.