The invention relates to pulp press screws with a double pitch of threads, for the use thereof in horizontal volumetric presses with two horizontal subscrews arranged in parallel and inserted into a longitudinal sleeve or envelope, common in the sugar industry, where the subscrews have a double pitch of threads at equal distance from the filtering sleeve, housed such that the two do not collide, the use thereof providing, combined with the incorporation of a scraper-cleaner edge on the outer end of the threads forming the two subscrews of the press, a substantial improvement in the yield of the assembly.
