Tsubaki offers Heavy Duty chains for applications that exceed the capabilities of Tsubaki ANSI G8 standard roller chain. Heavy Duty chain should be considered in the following situations:• Harsh environments where the chain will be subjected to heavy impact. • Compact drives for equipment or machines that must work in tight spaces. • When higher transmission power, allowable load or tensile strength is required. • When a lower rate of elastic elongation is required.H Series chain differs only from the ANSI G8 Series chain in the thickness of the link plates. The link plates have the same thickness as the link plates of the next larger pitch size in ANSI G8 Series. The increased thickness of the link plates provides a 9% greater capacity for absorbing shock loads. In short, H Series chains are especially suitable for situations where the load is heavy and operating speed is low (up to 50 m/min) or where operating conditions are severe.