Tb Woods TB-4J78 Sure-flex Sleeve Coupling Flange Size 4

Product Description

The TB WOODS TB-4J78 is a Type-J flange hub for Sure-Flex sleeve couplings, sized for coupling size 4 applications with a fixed round keyed bore of 7/8 inch. Manufactured from sintered steel with a carbon steel hub, this flange half transmits rotational power between shafts while absorbing shock loads, angular misalignment up to 1 degree, parallel misalignment, and end float through the flexible sleeve interface. It is rated to a maximum speed of 7,600 RPM and a maximum torque of 156 inch-pounds. Two set screws are included, positioned one over the keyseat and one at 90 degrees, providing secure shaft retention. Licensed HVAC, mechanical, and industrial service technicians install this component in rotating drive train assemblies.

This flange hub fits close-coupled drive configurations found in commercial and industrial rotating equipment. Typical applications include motors, pumps, compressors, blowers, mixers, and conveyors where shaft misalignment and vibration must be controlled. The 4-way flexing action of the Sure-Flex sleeve design makes this flange compatible with both EPDM and neoprene sleeve materials, supporting environments where chemical resistance and oil resistance are required. The inch-measurement bore and standard keyway sizing integrate directly with common shaft and keyseat dimensions used across industrial drive platforms.

Key Features

• Type-J close-coupled flange hub rated to 7,600 RPM and 156 inch-pounds maximum torque
• Fixed round keyed bore at 7/8 inch with bore tolerance of +0.0005 inch to +0.0015 inch
• 3/16 inch x 3/32 inch keyway accommodates standard keyed shaft connections
• Two set screws included: one over keyseat and one at 90 degrees for positive shaft lock
• Absorbs angular misalignment up to 1 degree (EPDM/neoprene sleeves), parallel misalignment, shock, and end float
• Oil-resistant and chemical-resistant construction suitable for demanding industrial environments

Compatibility

Designed for use with TB WOODS Sure-Flex size 4 sleeve coupling assemblies in motors, pumps, compressors, blowers, mixers, and conveyors. Compatible with both EPDM and neoprene Sure-Flex sleeves. No bushing is required for this bore configuration.

Installation Notes

Installation is performed by qualified mechanical technicians or millwrights. De-energize and lock out the drive motor before installing or removing any coupling component. Ensure the shaft and bore are clean and free of burrs before pressing the flange onto the shaft and seating the set screws. Verify sleeve condition and alignment within the specified angular and parallel misalignment limits before returning the drive to service.

Technical Specifications

• Coupling Size: 4
• Maximum Torque: 156 inch-pounds
• Maximum Speed: 7,600 RPM
• Maximum Angular Misalignment: 1 degree (EPDM/neoprene sleeves)
• Bore Diameter: 7/8 inch
• Bore Type: Fixed Round Keyed
• Bore Tolerance: +0.0005 inch / +0.0015 inch
• Keyway Size: 3/16 inch wide x 3/32 inch deep
• Outside Diameter: 2.5 inches
• Hub Diameter: 1 5/8 inches
• Hub Body Length: 27/64 inch
• Length Through Bore: 55/64 inch (approximately 0.86 inches)
• Screw Thread Size: 1/4 inch-20
• Included Hardware: 2 set screws
• Hub Type: Type-J Flange Close Coupled
• Hub Material: Carbon Steel
• Body Material: Sintered Steel
• Resistance Properties: Chemical Resistant, Oil Resistant
• Misalignment Types Accommodated: Angular, Parallel
• Weight: 0.4 pounds
• Country of Origin: United States

Standard Information

• Brand: TB WOODS
• Manufacturer Part Number: TB-4J78