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.