Method for reducing the reversible thermal expansion of a refractory molded product containing graphite on the basis of refractory material granulates, wherein the granulate grains of the material granulates are solidified to form a molded body, by a known binder and/or by a ceramic binding, and wherein a mixture of at least one refractory material, at least one binder, and a specific amount of flake graphite is produced and molded, wherein as the graphite, a mixture of at least two flake graphite types that differ in terms of their thermal expansion coefficient is used, wherein one flake graphite type predominates, in terms of amount, in the graphite mixture, and the other flake graphite type functions as an added graphite type, characterized in that the flake graphite types differ in a form factor FF that correlates with their thermal expansion coefficient, wherein the one graphite type, which makes up the predominant component of the graphite mixture, has a lower form factor FF and the added graphite type has a higher form factor FF, and wherein the form factor FF of each flake graphite type is determined before mixing, wherein each form factor FF is determined as follows: - screening of the flake graphite type and determination of the mesh width in μm of a screen that allows a specific percentage amount x in wt.-% to pass through (d x value), - determination of the averaged thickness c determined from a statistically sufficient number of measurements of graphite flakes, using an optical method, from at least one REM image of the respective flake graphite type, - calculation of the form factor FF using the formula: FF = d x value c wherein the mesh width is determined using an x value of x = 90, wherein flake graphite types are used for the graphite mixture, with the difference between their form factors FF (Δ FF) amounting to at least 10, and wherein the amount of the added graphite type having the greater form factor FF added to the flake graphite type having the smaller form factor FF amounts to minimally 3 and < 50 wt.-%, and particularly lies between 3 and 30 wt.-%. wherein as the graphite, a mixture of at least two flake graphite types that differ in terms of their thermal expansion coefficient is used, wherein one flake graphite type predominates, in terms of amount, in the graphite mixture, and the other flake graphite type functions as an added graphite type, characterized in that the flake graphite types differ in a form factor FF that correlates with their thermal expansion coefficient, wherein the one graphite type, which makes up the predominant component of the graphite mixture, has a lower form factor FF and the added graphite type has a higher form factor FF, and wherein the form factor FF of each flake graphite type is determined before mixing, wherein each form factor FF is determined as follows: - screening of the flake graphite type and determination of the mesh width in μm of a screen that allows a specific percentage amount x in wt.-% to pass through (d x value), - determination of the averaged thickness c determined from a statistically sufficient number of measurements of graphite flakes, using an optical method, from at least one REM image of the respective flake graphite type, - calculation of the form factor FF using the formula: FF = d x value c - screening of the flake graphite type and determination of the mesh width in μm of a screen that allows a specific percentage amount x in wt.-% to pass through (d x value), - determination of the averaged thickness c determined from a statistically sufficient number of measurements of graphite flakes, using an optical method, from at least one REM image of the respective flake graphite type, - calculation of the form factor FF using the formula: FF = d x value c wherein the mesh width is determined using an x value of x = 90, wherein flake graphite types are used for the graphite mixture, with the difference between their form factors FF (Δ FF) amounting to at least 10, and wherein the amount of the added graphite type having the greater form factor FF added to the flake graphite type having the smaller form factor FF amounts to minimally 3 and < 50 wt.-%, and particularly lies between 3 and 30 wt.-%.