Finished bore sprockets offer increased avoidance of shaft slippage more than minimum simple bore sprockets. Completed bores enable the roller chain sprocket to move larger loads with increased accuracy.
Toronto Gear Functions produces ready-to-ship finished bore sprockets that are produced with precision and so are fast and easy to install. Our catalogue Transmission Chain features a variety of finished bore sprockets that can match many precise overall performance requirements.
Toronto Gear Works stocks steel finished bore roller chain sprockets for #25 (0.250” pitch) roller chain. We 
share these steel sprockets in tooth counts which range from 9 to 72. All of our completed bore sprockets with a 0.500” bore or smaller are supplied with two set screws. Our finished bore sprockets with a 0.625” bore or greater have a standard keyway and two set screws. The keyway is usually centered on the tooth and the arranged screws can be found over the key at 90 degrees.
Steel finished bore #25 roller chain sprocket part numbers can be determined the following:
25BF + Tooth Count + “x” + bore size.
An example will be 25BF72x1-3/8. That is for a #25 roller chain. It has a “B” style sprocket which means that it has a hub. It includes a finished bore of just one 1.375” and it offers 72 teeth.