'Iron' in the Bible

The Lord was with Judah and enabled them to take possession of the hill country, but they could not drive out the people who were living in the valley because those people had iron chariots.

Then the Israelites cried out to the Lord, because Jabin had 900 iron chariots, and he harshly oppressed them 20 years.

Sisera summoned all his 900 iron chariots and all the people who were with him from Harosheth of the Nations to the Wadi Kishon.