Cupped flighting is manufactured to lean 18% in the direction of grain travel. This minimizes the breakage of delicate material such as beans and seed. When using this flight you must have a tube size 1” greater than the size of the flight. This flighting can also be used to provide a more efficient in-feed and higher outputs as well.

Cupped Flighting http://elmersflighting.com/index.php?option=com_content&view=category&layout=blog&id=13&Itemid=131