Brake Drums steel or iron?

Maye a Dev can help me with this one...
I have worked on many Trucks from1940's into the late 1970's
And notices brake Drums from those earlier times were sometimes Cast Iron "Iron" or always cast iron. can i use iron instead of steel in game. From {"rotorMaterial":"steel"}, To {"rotorMaterial":"iron"}, ?

This is of course for "Drums Brakes" i wanna see if there is a difference in Heat and Fade with the same settings as the steel ones with just the steel swapped out to iron? if there is any other materials i could use are those the only ones? i know engine blocks in-game use aluminum and iron so i figured id try.... i know aluminum on a drum wouldn't be a good idea because melting point but i dont think brake discs/drums melt like engine blocks do... so maybe aluminum would work alongside iron?