Movable conveyor slats (12) have side parts (74, 76) which rest on top parts of bearings (92). The bearings (92) have a generally U-shaped cross section and they fit on wings (52, 54, 54′) which extend outwardly and slope upwardly from the sides of a fixed conveyor slat (10, 10′). Fixed conveyor slats (10, 10′) have base portions (18, 18′) and upper insert portions (20, 20′). The inserts (20, 20′) have downwardly extending ribs (62, 64) on their sides which extend into upwardly opening grooves (48, 50) in the base portions (18). The movable slats (12) have web (80, 82) and lower flange portions (84, 86) which with the side parts (74, 76) of the slats (12) form laterally outwardly opening channels. The wings (52, 54, 54′) and the bearings (92) are received within the channels (88, 90).