Abstract: In the production of aluminum ingots by the direct chill casting process, in which the conventional chilled mold is equipped with a thermally insulated "hot top," smooth surfaced ingots are produced under conditions obtained by correlating of the length of the chilled mold, the casting rate and the head of molten metal in the hot top. Preferably the values of chilled mold length and metalostatic head are selected so as to be tolerant of some variation of metalostatic head which is difficult to avoid in the simultaneous operation of a large number of molds under level pour conditions.