The present invention has as objective a procedure for the oriented-grain magnetic sheet that provides particular operative hot rolling mill conditions of silicon steel slabs, by means which it is possible to highly contain the heterogeneities of hot rolled sheet re-crystallization. The use of these operative conditions permits to reduce the growing tendency of the crystallized grain during the annealing of the sheets at a final thickness that precedes the secondary oriented re-crystallization. Contemporarily, the particular operational conditions of hot rolling mill according to the invention permit a fine precipitation of secondary phases useful to the control of the grain growing, starting from a quantity of sulphur (S) and nitrogen (N) in matrix lower than corresponding provided by the conventional technologies and consequently disposable in metallic solid solution before the rolling after the heating of the slabs at temperature values lower than 1300° C.