This International Standard specifies a potentiometric or visual titration method for the determination of the mass fraction of manganese in alloyed steels. The method is applicable to mass fractions of manganese between 2 % and 25 %. Vanadium and cerium interfere with the measurement. If the mass fraction of cerium in the sample is less than 0,01 %, or the mass fraction of vanadium in the sample is less than 0,005 %, the interference is negligible. If the mass fraction of cerium in the sample is greater than 0,01 %, or the mass fraction of vanadium in the sample is greater than 0,005 %, a theoretical correction is necessary.