This flail is the right-side component mounted on the threshing rotor of a grain harvester. It pivots on its mounting hole and, as the rotor turns, the flail beats the crop material against the concave and grates to separate the grain from the straw and chaff. The flail's length and width determine the coverage pattern and the aggressiveness of the threshing action. A worn or bent flail reduces threshing efficiency and can cause uneven wear on the rotor assembly. When replacing, install the flail with the pivot bolt torqued to specification and verify free movement on the pin.