The cylinder is used for separating and classifying brokens. It is thus an indispensable machine in the process of selection for eliminating good rice from foreign bodies and grading long and short seeds and brokens.

From the loading mouth the product enters the machine which consists of a rotating cylindrical body and an internal basin. The cylindrical body, commonly known as the outer jacket is divided into two shells which can be easily assembled. The internal walls contain indented cavities whose size and shape vary according to the seeds to be processed. All the seeds with a length lower than that of the cavity are collected in the cavity itself and because of the effect of rotation they are raised upwards. The internal "V" shaped basin can rotate up to 360 according to the settings and it receives the seeds which after being raised by the indented cavities at a certain point fall because of the effect of gravity. The basin is equipped with a screw conveyor which transports the short seeds to a different exit from that of the long seeds which remain in the outer jacket.

The indented grading cylinder can be produced in version with different numbers of RPM and various inclinations as well as with an internal device for the uniform distribution of the seeds.