What is one of the main issues with wrought iron?

Wrought iron is known for its fibrous structure, which can lead to issues with performance, particularly in terms of its mechanical properties. This fibrous structure, while contributing to its ductility and toughness, can also create areas of weakness. If the material is subjected to stress, the presence of these fibers may result in unpredictable behavior under load, making it less reliable for certain applications compared to materials like steel, which has a more uniform microstructure.

When considering the other statements, wrought iron’s ductility means it is not too brittle for most applications, and it can indeed be worked by heating, making it flexible in crafting. Furthermore, wrought iron typically has a lower density compared to steel, contradicting the claim that it has a higher density. Thus, the issue associated with its fibrous structure is particularly relevant, showcasing how inherent material properties can impact performance and reliability.