A support roller (22) and a magnetic separator (10) incorporating the same utilizes a plurality of roller segments (42) which are pivotally mounted to an axle member (24) such that the roller segments (42) are radially spaced from the axle member (24) and extend in longitudinal parallel relation thereto. The opposite ends (44, 46) of the roller segments (42) can move toward and away from axle member (24). A first pair (61, 62) of roller segments (42) are interconnected by a linkage (64) that causes the first ends (44) of the pair to move correspondingly and, due to the pivot mount (52), the second ends (46) move correspondingly to one another in a direction opposite the movement of the first ends (44). Preferably, at least four equiangularly spaced roller segments (42) are employed and a pair of linkages (64) interconnect each pair of opposed roller segments (42). Several different linkage assemblies (64) are disclosed. Where the support roller (22) is incorporated in a magnetic separator (10), a support frame (18) rotatably supports a magnetic roller (12) and the support roller (22). A thin conveyor belt (20) extends around the rollers to receive particulate material for separation, and a drive rotates the two rollers.