Abstract: A sieve for use in a combine harvester includes a plurality of longitudinal parallel rails lying in a common plane of the sieve including two spaced side rails and at least one intermediate rail. Each rail has a row of holes supporting a plurality of parallel cross wires of square cross-section extending generally at right angles to the rails with each wire passing through a respective one of the holes. Each wire carries a plurality of separate louver sections thereon, each louver section spanning a distance between a respective pair of the rails. A common adjustment member for the wires causes common rotation of each of the wires about a longitudinal axis to cause rotation of the louver sections to adjust the louver openings. Each louver section has formed a square sleeve through which the wire passes without welding to the wire so that the wire can be pulled longitudinally relative to the louver sections for removal of individual louver sections for repair.