'Iron' in the Bible

And Yahweh was with Judah, and he took possession of the hill country, but they could not drive out the inhabitants of the plain because they [had] chariots of iron.

And the {Israelites} cried to Yahweh, as he [had] nine hundred iron chariots, and he oppressed the {Israelites} {cruelly} for twenty years.

Sisera summoned all his chariots--all nine hundred chariots of iron--and the entire army that [was] with him from Harosheth Haggoyim to the wadi of Kishon.