A combine harvester has the crop flow through the machine in one axial direction from pick up to the final separator. The threshing stage has a pre-separator (27) into which the crop is fed tangential. The flailing arms of the threshing stages are in a staggered arrangement as are the threshing baskets. The threshed crop is fed through a final separator leaving the straw and chaff to be handled separately. The relative alignment of the separate stages produces an axial work flow with a high separation efficiency.
