Wrought iron is a type of iron that possesses the property of being forged and hammered while it is still at very high temperatures (2000 °F) It has a low percentage of carbon content (0.08%). These qualities made it ideal for the manufacturing of weapons.
Cast Iron has a much greater carbon content (>2%) and a higher melting temperature (>2735 °F). This made it less feasible for the technology of the age to perform.