Machinists, fabricators, and go-kart builders – here's a basic but essential sprocket. This is a #40 roller chain sprocket, B-type (standard), with 9 teeth and a 5/8-inch bore (that's the hole in the center for your shaft). The model/MPN is 40B9-5/8/1PK from SUMMIT COLLARS. It's brand new, made in China. This is a single sprocket, ideal for light to medium-duty power transmission applications like conveyor drives, machinery, or small vehicles. The 9-tooth count gives a decent speed ratio when paired with a larger sprocket on the driven end. You'll need a #40 roller chain to fit it. The 5/8\ bore is common, but double-check your shaft diameter. Installation usually requires a keyway and set screws (check if included) to secure it to the shaft. It's a simple, no-frills component that gets the job done. Always pair sprockets and chains from the same size family (#40 in this case) for proper operation. A reliable piece for DIY mechanical projects.
