Iron Sword notes, compiled from various posts to rec.games.frp.dnd.
Descriptions here are very sparse. Many steps are ommitted.
To make a regular sword
Heat iron
Shape it
Cool it
Repeat
To make a cold-worked sword
Bang the iron into the shape you want.
Cold-iron weapons are weak and hard to make.
To make a cast-iron sword
Pour the iron into a mold.
Cast Iron is a ferrous alloy, the carbon content of which is greater than the maximum solubility in austenite at the eutectic temperature (Materials Science and Engineering, an Introduction; Callister)