Roller chain or bush roller chain is the kind of chain drive mostly used for transmitting of mechanical power on many types of domestic, industrial and agricultural machinery, including conveyors, wire- and tube-drawing machines, printing presses, vehicles, motorcycles, and bicycles. It contains a Auto Chain series of short cylindrical rollers held together by part links. It is driven by a toothed wheel known as a sprocket. It really is a straightforward, reliable, and efficient[1] method of power transmission.

Though Hans Renold is credited with inventing the roller chain in 1880, sketches by Leonardo da Vinci in the 16th century show a chain with a roller bearing.