press rolls for washing or dewatering pulp are disclosed including a core , a mantle section attached around the core , at least one perforated roll plate extending around the circumference of the press roll , and including a plurality of mounting openings disposed between the end edges of the perforated roll plate and distributed around the entire circumference of the press roll , and a plurality of fixing pins corresponding to the mounting openings , each being anchored to the mantle section and surrounded by the corresponding plurality of mounting openings whereby movement of the perforated roll plate relative to the mantle section in a circumferential direction of the press roll is prevented .