Steel

"Steel" in the Authorized Version of 2 Samuel 22:35, Job 20:24, and Psalm 18:34 renders the Hebrew nechoshet, more accurately translated "bronze" or "brass" in the Revised Version. The expression "bow of brass" (or "steel" in the AV) indicates a bow of exceptional hardness and strength — so hard that only a divinely strengthened warrior could bend it. True steel (iron alloyed with carbon to increase hardness) was not widely available in the biblical world, though iron itself was increasingly common from the Iron Age onward.

Similarly in Jeremiah 15:12 the same word is translated as "northern iron and steel" in the AV but rendered "iron and bronze" in more modern versions. The poetic context suggests the metaphorical meaning of indestructible, unbreakable strength — a strength that only God can provide to his servant or that his judgment can overcome.