The threshing line consists of threshers or beaters, which mechanically separate the stem from the leaf, and classifiers or separators, which detach the stems from the strips by means of an air flow.

Threshing
Because it is impossible to detach all of the stems from the strips in the first stage of the threshing process, the heavy particles proceed to second-, third-, and fourth-stage threshers and classifiers. At each stage, the threshing process separates parts of the leaf by means of an airlock and then sieves them to remove the smallest particles.

After the fourth and final stage, any remaining flaggy stem is classified, then recycled to remove the flag or final portion of the leaf.
By the end of this process the stem has been completely separated from the leaf. The leaf and stem then proceed to storage silos for the redrying process.