Quick video showing the differences between a steel and cast iron brake hub on a Ford Model A. While original brake hubs were made of steel, cast iron is more desirable over steel because they dissipate the heat better and are thicker than steel hubs, resulting in better brake performance and less fading under strenuous braking conditions. Steel brake hubs are fine if properly fitted to your Model A. But when it comes time to replace your brake hubs, consider cast iron as a replacement as a safety precaution.