Speaking from personal experience as a welder, steel is a lot easier to work with than iron. If someone manages to break a piece of steel (which isn’t easy), repairing it is a simple matter of properly positioning the pieces and welding them together. In contrast, repairing a cracked or damaged piece of iron means heating the whole piece back up to nearly molten temperatures, then carefully welding it in stages--with pauses to reheat the piece--while sometimes giving it a whack with a hammer and hoping you don’t hear the tell-tale ping of a crack forming somewhere else. Iron is a finicky material.

Cast Iron Ball Caps