Abstract: Harvested grain in the form of including ears, pods to be threshed are transported axially into an inclined threshing zone. Grain is liberated and falls through a sieve forming a bottom of the threshing zone. Most of the lightweight material or chaff is carried to an exit by a fan generated airflow stream. Grain and some chaff falling through the sieve are collected in a trough below the sieve. A fan generated auxiliary airflow stream carries most of the remaining chaff to the exit. The larger portion of the grain slides down the trough to exit. The balance of the grain with virtually no entrained chaff exits the trough via an auxiliary grain exit. Transverse baffles, in tandem, opposing relationship, cause airflow to be circuitous to promote grain in preference to chaff to enter the exit. A final cleaning step may be performed in a cleaning apparatus.