Roller chain sprockets, sometimes called single-strand sprockets, have a series of tooth cogs and chains around a central bore and so are used in mixture with roller chains to move conveyors and other industrial machinery. Fixed bore sprockets are designed to fit a particular shaft size you 
need to include a keyway and setscrew so they’re ready to install. Ordinary bore sprockets are manufactured without a keyway or arranged screw. Keyways or arranged screws could be machined to the specific size necessary by the prevailing shaft and app. Bushed bores have significantly more clamping region around the shaft to supply a secure fit for high torque or high-power applications when the shaft reaches risk of slipping, such as for example paper milling and agricultural machinery.
