Mold for the continuous casting of preliminary sections, in particular double T-shaped preliminary sections, such as beam blank sections or similar sections, wherein all the interior walls of the mold in a mold passage have a tapered course running linearly from top to bottom, this tapered course being dimensioned depending on the degree of shrinkage of the cast strand and produced by machining the interior walls. In this manner, it is possible to optimally adjust the diameter of the mold to the shrinkage process of the cast strand in the region of the mold passage, even for large-sized sections.