Abstract: An iron alloy comprises 1.5-4.5% carbon, 1.5-4.5% silicon, at least 1.0 to 6.5% molybdenum and optionally copper and/or nickel wherein (% Mo+% Ni+% Cu) does not exceed 6.5%, balance iron and incidental impurities. The alloy is preferably spheroidal graphite cast iron. The alloy is especially useful in manufacturing brake disc rotors.