Roller chain or bush roller chain is the type of chain drive mostly used for transmission of mechanical power on many kinds of domestic, commercial and agricultural machinery, including conveyors, wire- and tube-drawing devices, printing presses, vehicles, motorcycles, and bicycles. It includes a series of brief Auto Chain cylindrical rollers held with each other by aspect links. It is 9k=driven by a toothed wheel known as a sprocket. It is a simple, reliable, and efficient[1] means 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.