Tubal-Cain is the first-mentioned worker in iron (Genesis 4:22). The Egyptians wrought it at Sinai before the Exodus. David prepared it in great abundance for the temple (1 Chronicles 22:3: 29:7). The merchants of Dan and Javan brought it to the Market of Tyre (Ezek. 27:19). Various instruments are mentioned as made of iron (Deuteronomy 27:5; 19:5; Joshua 17:16, 18; 1 Samuel 17:7; 2 Samuel 12:31; 2 Kings 6:5, 6; 1 Chronicles 22:3; Isaiah 10:34).

Figuratively, a yoke of iron (Deuteronomy 28:48) denotes hard service; a rod of iron (Psalm 2:9), a stern government; a pillar of iron (Jeremiah 1:18), a strong support; a furnace of iron (Deuteronomy 4:20), severe labour; a bar of iron (Job 40:18), strength; fetters of iron (Psalm 107:10), affliction; giving silver for iron (Isaiah 60:17), prosperity.

Noah Webster's New International Dictionary of the English Language

1. (n.) The most common and most useful metallic element, being of almost universal occurrence, usually in the form of an oxide (as hematite, magnetite, etc.), or a hydrous oxide (as limonite, turgite, etc.). It is reduced on an enormous scale in three principal forms; viz., cast iron, steel, and wrought iron. Iron usually appears dark brown, from oxidation or impurity, but when pure, or on a fresh surface, is a gray or white metal. It is easily oxidized (rusted) by moisture, and is attacked by many corrosive agents. Symbol Fe (Latin Ferrum). Atomic weight 55.9. Specific gravity, pure iron, 7.86; cast iron, 7.1. In magnetic properties, it is superior to all other substances.

2. (n.) An instrument or utensil made of iron; -- chiefly in composition; as, a flatiron, a smoothing iron, etc.

3. (n.) Fetters; chains; handcuffs; manacles.

4. (n.) Strength; power; firmness; inflexibility; as, to rule with a rod of iron.

5. (n.) Of, or made of iron; consisting of iron; as, an iron bar, dust.

6. (n.) Resembling iron in color; as, iron blackness.

7. (n.) Like iron in hardness, strength, impenetrability, power of endurance, insensibility, etc.;

8. (n.) Rude; hard; harsh; severe.

9. (n.) Firm; robust; enduring; as, an iron constitution.

10. (n.) Inflexible; unrelenting; as, an iron will.

11. (n.) Not to be broken; holding or binding fast; tenacious.

12. (v. t.) To smooth with an instrument of iron; especially, to smooth, as cloth, with a heated flatiron; -- sometimes used with out.

13. (v. t.) To shackle with irons; to fetter or handcuff.

14. (v. t.) To furnish or arm with iron; as, to iron a wagon.