Hastings' Dictionary of the Bible (1898)
STEEL. Ps 18:34. This word occurs four times in our English Bible, and should in every instance be rendered "copper." It is not certain that the ancient Hebrews were acquainted with steel, though it seems to have been known to the Egyptians. Iron from the north. Jer 15:12, may denote a superior kind of the metal, or that which had been unusually hardened.