There could be some different ways to answer,but I would have to say it would be copper.Brass is made from combining copper and zinc,while copper can also be an alloying agent for mild steel.However mild steel can have many different alloying agents in it.Carbon is the most prevalent in steel but there would be none in brass since it is a non-ferrous metal.
Zinc
Equivalent material of mild steel ;is:206
what the neccecities of shear test of brass & mild steel
Mild steel
mild steel .... and "Al"
Cast iron
Galvinised mild steel,
Charles Babbage used mild steel, brass, metal, and gears
cheapest material is Mild steel having very good properties of shaft.
Cast iron, SS, Mild Steel
Mostly mild steel but I don't know the grade.
mild steel is heavier