In one embodiment of the present disclosure, a drive chain system (22, 24) for a spiral conveyor belt (34) includes inner (52) and outer (62) drive chains driving the spiral conveyor belt, the inner and outer drive chains each including a plurality of links (70) defined by a plurality of first (72) and second (74) pitches connected by linking pins (84, 86) extending through holes (80, 82) in the pitches, wherein at least a portion of the linking pins of at least one of the inner and outer drive chains are hardened and/or dissimilar linking pins which are harder on an outer surface than other components in the inner and outer drive chains.