Abstract: A centrifugal sifter having a rotatable shaft with an auger and paddles located thereon. An inlet manifold presents material to be sifted to the auger. A cylindrical screen surrounds the paddles and is in turn confined within an outlet manifold where material sifted through the screen is collected and discharged. Material not passed through the screen exits the opposite end of the screen from the auger and is directed outwardly through an outlet manifold. The cylindrical screen includes circular beads at each end. These beads are positioned over short cylindrical elements and held between mounting plates and locking plates to retain the screen at each end. One of the screen clamps is slidably mounted in the centrifugal sifter and is held in place to tension the cylindrical screen by a resilient tensioning assembly. Rods extend to the slidably mounted screen clamp. Pneumatic expansion elements using air bags or pneumatic cylinders bias the rods to tension the cylindrical screen.