The influence of the dimensions of square-patterned pyramidal protuberances on a spheronisation plate on pellet yield, size and shape distributions, surface tensile strength and surface morphology was investigated using a 45 wt% microcrystalline cellulose/water paste. Tests were conducted using four extrudate diameters (1.0, 1.5, 2.0 and 2.5 mm) generated by screen extrusion and seven plate geometries, including a flat plate as a control. Geometrical analyses of the protuberance shapes provide some insight into the observed differences. Sharper protuberances reduced yield (promoting breakage and attrition) but tended to give narrower size distributions and less even pellet surfaces. The pellet yield for 1 mm extrudates was also subject to losses caused by fragments passing through the 1.0 mm gap between the plate and the spheroniser wall. Pellet tensile strengths were noticeably greater for 1.0 mm diameter extrudates, which is attributed to the greater extensional strain imparted on the paste during the extrusion step. For some geometries there is an optimal ratio of extrudate to protuberance dimensions. (C) 2018 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.