Abstract: A system for improving the operating efficiency of screw presses which express fluids from fibrous material. This system includes a plurality of worm sections and collars and a hollow main shaft. Fluids are allowed to pass into the hollow shaft through one or more screen bar sections, fitted over the collars. The area of the collar housing beneath the screen bars is generally funnel-shaped toward the longitudinal rotational axis of the shaft, having a drain opening near the apex of the funnel configuration to allow expressed fluids to exit into the hollow drive shaft or into a conduit therein. The worm flights may include hardened wear resistant inserts in the outer peripheral surface which may be integrally cast into the worm section. The worm sections which mate to form a single divided worm may be identical and therefore reversible to reduce production and inventory costs.