Iron Forge
Iron Forge follows Bronze Polishing in the metallurgy technology branch. It costs 35 red technology points.
Prerequisite and cost
Section titled “Prerequisite and cost”Bronze Polishing is the prerequisite. Iron Forge costs 35 red technology points.
Unlocks
Section titled “Unlocks”The unlock list contains 
Iron Ingot, 
Supply: Iron and 
Furnace II.