Finished bore sprockets provide increased prevention of shaft slippage more than minimum simple bore sprockets. Finished bores enable the roller chain sprocket to 
go larger loads with increased accuracy.
Auto Chain Toronto Gear Functions produces ready-to-ship completed bore sprockets that are manufactured with precision and are fast and simple to install. Our catalogue includes a variety of finished bore sprockets that can match many precise functionality 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 completed bore sprockets with a 0.625” bore or greater have a typical keyway and two set screws. The keyway is certainly centered on the tooth and the established screws are located 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 would be 25BF72x1-3/8. This is for a #25 roller chain. It has a “B” style sprocket which implies that it includes a hub. It has a finished bore of 1 1.375” and it provides 72 teeth.