the grinding point of the grinding wheel seated upon a dressing support 21 which is displaceable in the direction of the double headed arrow 20 is a dressing device 22 which is arranged angularly rigid and serving for dressing the end surface of the grinding wheel or disk 2 and an angularly rigidly arranged dressing device 23 for the dressing of the jacket or outer surface of such grinding wheel as well as a feeler device 25 which is pivotable about a point 24 located at the region of the upper grinding edge associated with the feeler device 25 is a feeler 11 constructed as a feeler diamond the feeler 11 is attached to a pivotable feeler lever 26 which indicates its position in conventional manner by means of a contact 27 the grinding spindle 14 is axially positionally readjusted upon wear of the end surface of the grinding wheel 2 as far as the grinding wheel or disk 1 is concerned there is provided an arrangement which is the mirror image of that shown in fig6 and thus need not be further illustrated the adjustment or setting conditions are determined by virtue of the fact that there is chosen a tooth width w s which is greater or as closely as possible smaller than the ideal tooth width w sv the ideal tooth width w sv corresponds according to the showing of fig3 to a distance along the tangent to the base circle which is bounded by the point of intersection f.