'Iron' in the Bible

The LORD was with the army of Judah, and they captured the hill country, but did not expel the inhabitants of the valley because they were equipped with iron chariots.

The Israelis cried out to the LORD, because of his 900 iron chariots. Jabin oppressed the Israelis forcefully for twenty years.

So Sisera gathered his iron chariots together from Harosheth-haggoyim all 900 of them, along with all the people who were assigned to them and they assembled at the Kishon River.