Finished bore sprockets provide increased avoidance of shaft slippage over minimum basic bore sprockets. Completed bores enable the roller chain sprocket to move larger loads with increased accuracy.
Toronto Gear Functions produces ready-to-ship completed bore sprockets that are manufactured with precision and are fast and easy to install. Our catalogue features a variety of completed 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 metal sprockets in tooth counts ranging from 9 to 72. All of our 
completed bore sprockets with a 0.500” bore or smaller are supplied with two set screws. All of our completed bore sprockets with a 0.625” bore or greater have a standard keyway and two set screws. The keyway is centered on the tooth and the set screws are located over the main element at 90 degrees.
Steel finished bore #25 roller chain sprocket component numbers could be Transmission Chain 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 provides 72 teeth.