Jeremiah 15:12. Rather copper, which being mixed with "iron" by the Chalybes near the Euxine Pontus formed the hardest metal, "the northern iron and the steel." "Shall (ordinary) iron break" this? No more can the Jews break the hardier Chaldees of the N. So in Job 20:24; Psalm 18:34, translated "brass" or "copper." Bronze was anciently used for strengthening arms.