In wheat milling, it is particularly necessary that the grist particle size-distribution entering and exiting each plansifter compartment of the wheat mill to be determined so that the appropriate geometrical characteristics of flutes, grinding rolls and their functional parameters can be chosen and the characteristics of the sieves braids to be established to optimize flour, middling, and semolina yield and quality of them. The paper presents the particle size-distribution of wheat going through each break, in a five-break roller mill system with a capacity of 4.2 t/h and equipped with a semolina sorting compartment (divisor). The particle size distribution data where fit to the Rosin-Rammler distribution equation.