Finished bore sprockets offer increased avoidance of shaft slippage over minimum ordinary bore sprockets. Finished bores allow for the roller chain sprocket to go larger loads with increased accuracy.
Toronto Gear Functions produces ready-to-ship finished bore sprockets that are manufactured with precision and so are fast and simple to install. Our catalogue features a variety of completed bore sprockets that can match many precise efficiency requirements.
Toronto Gear Works stocks steel completed bore roller chain sprockets for #25 (0.250” pitch) roller chain. We stock these metal sprockets in tooth counts ranging from 9 to 72. Our completed bore sprockets with a 0.500” bore or smaller are given two set screws. Our finished bore sprockets with a 0.625” bore or greater have a standard keyway and two arranged screws. The keyway is usually centered on the tooth and the established screws are located over the key at 90 
degrees.
Steel finished bore #25 roller chain sprocket component numbers can be determined the Drive Chain following:
25BF + Tooth Count + “x” + bore size.
An example would be 25BF72x1-3/8. This is for a #25 roller chain. It has a “B” style sprocket which implies that it has a hub. It includes a finished bore of just one 1.375” and it has 72 teeth.