'Iron' in the Bible

So the metal-worker put heart into the gold-worker, and he who was hammering the metal smooth said kind words to the iron-worker, saying of the plate, It is ready: and he put it together with nails, so that there might be no slipping.

The iron-worker is heating the metal in the fire, giving it form with his hammers, and working on it with his strong arm: then for need of food his strength gives way, and for need of water he becomes feeble.

I will go before you, and make the rough places level: the doors of brass will be broken, and the iron rods cut in two:

Because I saw that your heart was hard, and that your neck was an iron cord, and your brow brass;

See, I have made the iron-worker, blowing on the burning coals, and making the instrument of war by his work; and I have made the waster for destruction.

In place of brass, I will give gold, and for iron silver, and for wood brass, and for stones iron: and I will make Peace your judge, and Righteousness your overseer.