The results of the study of treatment quality of wheat grain heap in grain cleaning machines ОЗС–50, Petkus U–80–12G, Petkus 12, 3–3,5 and Cimbria Delta 146 in cleaning mode and ОЗФ–80 in fractionation mode are given. For fractionation of grain heap on the machine ОЗФ–80 grading sieve have been established with the holes of 2.6 mm width. In the traditional treatment of grain heap, content of biologically inferior grain decreased in 1.26, crushed grain in 2.3 and contaminants in 1.9 times.

In the study grain pile of winter wheat Bezenchukskaya that came from the harvesting was fractionated using laboratory screening with the installation of sieves with hole sizes intervals of 0.2 mm. For selected fractions weight of 1000 grains, the level of injury, laboratory germination of seeds, vitreous grains and gluten content were determined. Processing the results of studies was performed using the methods of mathematical statistics and statistical software package. The studies found that the laboratory germination increases with the weight of 1000 grains and reduction of injury to corn.