Traditional large cast iron couplings, used to connect shafts in large bore applications found in lumber, steel, rail, recycling, and paper industries, are manufactured from iron and are extremely heavy.

Large cast iron couplings have a bulky design that requires extra room in order to accommodate the oversized outside diameter of the unit. The sheer size of these antiquated couplings puts unnecessary stress on the shaft, and poses risk to damaging the shaft and associated components. In order to attain necessary torque for these applications, cast iron couplings encompass the use of a keyway leading to issues such as wallowing, backlash, fretting corrosion, and fatigue failure, commonly associated with keyways.