Abstract: Screw press arrangement having two or more screw threads arranged side-by-side in a relatively tightly fitting press basket having openings for the drainage of fluid from the material which is fed into the press. At the feeding-in portion the core of the screw element has a relatively small diameter while the screw threads have a large diameter and at the discharge portion the core of the screw elements has a relatively large diameter while the screw threads have a small diameter. Cylindrical sections of the press basket are employed over the largest part of the length of the press and conically tapered sections of the press basket serve as transition and discharge sections respectively. Provision is made for about 20% of the total length of the screw element in the form of the discharge portion to have a uniformly increasing core diameter towards the discharge end and a uniformly decreasing press basket inner diameter.