cogs and chains Roller chain sprockets, sometimes called single-strand sprockets, have a series of teeth around a central bore and are used in mixture with roller chains to move conveyors and other commercial machinery. Fixed bore sprockets are made to fit a specific shaft size and include a keyway and setscrew therefore they're ready to install. Simple bore sprockets are manufactured with out a keyway or established screw. Keyways or arranged screws could be machined to the exact size necessary by the existing shaft and application. Bushed bores have more clamping area around the shaft to provide a secure match for high torque or high-power applications when the shaft is at risk of slipping, such as for example paper milling and agricultural machinery.