Indented cylinders separator are used for length grading of all granular materials such as wheat, oat,maize, rice, fine, lentils,stones from peas, sticks from sunflower or sugar beet, plastic particles, etc.,as well as for the extraction of unwanted short or long admixtures. Through the inlet housing, the granular material to be graded flows into theinterior of the rotating cylinder whose cover is provided with special deep drawn tear-drop or spherical shaped pockets for the most precise length separation. The grains that embed themselves fully into the indents will be lifted, and after a certain distance (adjustable to suit),will fall out of the pockets under gravity into the trough (Trough-Product), and will be discharged by means of a conveying screw.