The "bow of steel" in (A.V.) 2 Samuel 22:35; Job 20:24; Psalm 18:34 is in the Revised Version "bow of brass" (Hebrews kesheth-nehushah). In Jeremiah 15:12 the same word is used, and is also rendered in the Revised Version "brass." But more correctly it is copper (q.v.), as brass in the ordinary sense of the word (an alloy of copper and zinc) was not known to the ancients.

Noah Webster's New International Dictionary of the English Language

1. (n.) A variety of iron intermediate in composition and properties between wrought iron and cast iron (containing between one half of one per cent and one and a half per cent of carbon), and consisting of an alloy of iron with an iron carbide. Steel, unlike wrought iron, can be tempered, and retains magnetism. Its malleability decreases, and fusibility increases, with an increase in carbon.

2. (n.) An instrument or implement made of steel

3. (n.) A weapon, as a sword, dagger, etc.

4. (n.) An instrument of steel (usually a round rod) for sharpening knives.

5. (n.) A piece of steel for striking sparks from flint.

6. (n.) Fig.: Anything of extreme hardness; that which is characterized by sternness or rigor.

7. (n.) A chalybeate medicine.

8. (n.) To overlay, point, or edge with steel; as, to steel a razor; to steel an ax.

9. (n.) To make hard or strong; hence, to make insensible or obdurate.

10. (n.) Fig.: To cause to resemble steel, as in smoothness, polish, or other qualities.

11. (n.) To cover, as an electrotype plate, with a thin layer of iron by electrolysis. The iron thus deposited is very hard, like steel.