Martin Sprocket & Gear Quadra-Flex Coupling Hub, size 6H with a 1-3/8 in bore, is a hub component designed for the Quadra-Flex coupling system. It provides the shaft connection portion of the coupling used to transfer torque between shafts in power-transmission assemblies. The 1-3/8 in bore denotes the shaft diameter it fits, making it the correct hub for assemblies configured in the 6H/Quadra-Flex lineup.
