Abstract: Segments for briquetting and compacting rolls which include seats in the roll core and means for clamping the segments in place. The segments define side walls which are in facing relationship when the segments are assembled with the roll core. The side walls each define a groove and a sealing profile in the form of a rod of ductile material is positioned between opposed grooves. When the segments are clamped in place, the profiles are compressed and plastically deformed whereby an impenetrable barrier to the passage of particles between and beneath the segments is provided.