This machine is used for length grading of all granular materials, such as wheat, oat, maize, rice, lentils, etc. from unwanted elements as well as for the extraction of short or long admixtures. The size of grains can vary between 1.0 mm and 24 mm. Depending on the required grading the incoming product is sorted according to roundness or length. Working principle: The product passes from the inlet housing into the interior of the rotating cylinder, the cover of which is provided with impressed pockets or so-called indents. The grains that embed themselves in the indents fall out of the pockets into the trough and are discharged by a screw conveyor, while all grains which are larger than the indents remain inside the shell and are carried to the outlet where the shell empties into the outlet casing.