Flat chain is a form of chain used chiefly in agricultural machinery. Early machinery made extensive use of flat chain. It has been gradually replaced in most applications by roller chain

Roller chain

Roller chain or bush roller chain 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 simple machines like...

, which is quieter, lasts longer, and requires less frequent retensioning.

Modern flat chain is made from stamped steel. Individual links can be put together or taken apart using simple tools, unlike roller chain which requires a master link or special splicing equipment.

Today, flat chain is used most often for conveyor belt

Conveyor belt

A conveyor belt consists of two or more pulleys, with a continuous loop of material - the conveyor belt - that rotates about them. One or both of the pulleys are powered, moving the belt and the material on the belt forward. The powered pulley is called the drive pulley while the unpowered pulley...

s, because it lends itself well to the attachment of slats, flights, buckets, and prongs used to move material. Such attachments can be welded on in the field, or can be purchased ready-made on a single link (or pair of links where the conveyor uses two chains) and then spliced into a loop of chain.

Older forms of flat chain were made of iron. Though the sprocket

Sprocket

A sprocket or sprocket-wheel is a profiled wheel with teeth, cogs, or even sprockets that mesh with a chain, track or other perforated or indented material. The name 'sprocket' applies generally to any wheel upon which are radial projections that engage a chain passing over it...

s are compatible with modern chain, the two types cannot be spliced together.