Lovejoy 69790400069 Rigid Coupling Hub 1.25in Bore Carbon Steel

Product Description

The LOVEJOY 69790400069 is a rigid coupling hub designed for direct shaft-to-shaft power transmission in mechanical drive applications. It features a 1.25-inch bore and a 4.75-inch outside diameter, machined from carbon steel for durability under load. A 0.25-inch wide by 0.125-inch deep keyway is cut into the bore, allowing positive rotational engagement with a keyed shaft. Rigid coupling hubs like this one are installed by millwrights, mechanical contractors, and industrial maintenance technicians where precise shaft alignment is maintained and no flex or misalignment compensation is required.

This hub is suited for use in industrial and commercial mechanical drive systems, including pumps, fans, compressors, and conveyor drives. It is installed as one half of a rigid coupling assembly, mating with a corresponding hub and a center element or sleeve depending on the coupling system in use. Carbon steel construction makes it appropriate for general-purpose indoor or protected-environment drive train applications where corrosion exposure is limited.

Key Features

• 1.25-inch bore diameter for direct shaft mounting
• 4.75-inch outside diameter for coupling assembly fitment
• 0.25-inch wide by 0.125-inch deep keyway for positive key engagement
• Carbon steel construction for strength and machinability
• Rigid design maintains zero-backlash shaft alignment under torque

Compatibility

Designed as an OEM-style replacement or service hub for rigid coupling assemblies requiring a 1.25-inch bore with a 0.25-inch by 0.125-inch keyway and a 4.75-inch outside diameter.

Installation Notes

Installation is typically performed by a millwright or mechanical technician. Ensure the drive shaft and mating coupling components are fully de-energized and locked out before mounting. Verify shaft and bore dimensions along with keyway fit before pressing or driving the hub onto the shaft. Rigid couplings require precise shaft alignment; check angular and parallel alignment to manufacturer tolerances before final tightening.