Abstract: A sifting or screening device includes inner and outer concentric screened enclosures which rotate about a common axis. An inlet is provided at one axial end of the inner enclosure and an outlet is provided at the opposite axial end of the enclosures for the material that was too large to pass through the openings defined by the screens. An inclined dead plate or baffle member is provided at the inlet to prevent material fed in through a chute from impinging directly on the screen material and a pressurized air system presents a pulsating curtain of air to disengage material which has become lodged in the screen. A novel support system includes a circular support surface at the inlet end which rides on a pair of bearings and a central axle coincident with the axis of rotation driven by a motor at the outlet end. The axis of rotation is caused to lie at a small angle to the horizontal so that material which will not pass through the screens will slowly fall toward the outlet end of the enclosures.