Side roller chain is used for free flow conveyance in the electric, electronic equipment, and auto parts industries. This receives the loads of conveyed articles by side rollers, and is used for a free flow conveyor running on a rail. Since the number of rollers for receiving the loads of conveyed articles is large, a side roller chain can convey heavier articles than a top roller chain made of the same material. Furthermore, since the center of gravity of the chain is low, stability is also good. All the connecting links of side roller chain are of cotter types.