Roller chains is the type of chain drive most commonly used for transmission of mechanical power on many kinds of domestic, industrial and agricultural machinery, including conveyors, wire– and tube–drawing machines, printing presses, cars, motorcycles, and bicycles. It consists of a series of short cylindrical rollers held together by side links. It is driven by a toothed wheel called a sprocket. It is a simple, reliable, and efficient means of power transmission. Most of the chain is composed of chain plate chain pin sleeve and other components.

Classification by pitch: common names are: 4 points (P=12.7), 5 points (P=15.875), 1 inch (P=25.4), 1 and a half inches, etc.