Abstract: A self cleaning rotary screen apparatus is disclosed which comprises an outer shell formed from a plurality of spaced cylindrical hoops that are welded to a plurality of longitudinal bars which extend the full length of the shell. The hoops are variably spaced along the length of the shell to provide different sized screen openings. In addition, for aiding in the screening operation and for keeping the material moving through the screen, an internal helical blade construction comprising a multiple helix at the entrance to the screen and a single helix thereafter is welded to the longitudinal bars over the full length of the shell.