Coupling roller chains are two-row (duplex) chains that are cut to specific pitch lengths to accommodate coupling sprockets. What sets our chains apart from others is the use of high-grade precision steel components that have been shot-peened, heat-treated, and pre-loaded for maximum performance and minimal elongation. Selecting the right coupling chain is important; thankfully, this is an easy process due to the clear manufacturing marks that are typically on the sprockets. For example, a 4012 sprocket requires a 4012 coupling roller chain. If there are no manufacturing marks on the sprocket, count the amount of teeth on it, and determine the pitch for chain size. A 12-tooth sprocket will take a 12-pitch section of chain, the part number is broken into two sections 40-12, the 40 represents the chain pitch size (1/2") and the 12 represents the length (12-pitches). We supply both ANSI and Metric coupling roller chains. For more information or to get a quote, contact our customer support team, and we will be happy to assist you!