Overview
The Falk 1090T31/35 grid coupling shaft hub (RSB 0258641) is a precision-engineered Steelflex component from Rexnord designed for demanding industrial coupling applications. This shaft hub combines high torque capacity with flexible coupling characteristics, eliminating the need for periodic maintenance when properly lubricated with Falk Long Term Grease (LTG).
Key Features
- T31/T35 Series Steelflex design—delivers reliable torsional flexibility and high torque transmission
- Rough Stock Bore (RSB)—ready for custom machining to your exact shaft diameter
- Steel construction—durable and compatible with industrial gear drives and motor couplings
- No keyway required—straight bore design accommodates various installation methods
- 5-year lubrication warranty—backed by Rexnord when installed with Falk LTG grease
Technical Specifications
- Coupling Size: 1090T
- Bore Range: 1-1/16″ to 4″ (rough stock for custom boring)
- Hub Outside Diameter: 5.62″
- Flange Outside Diameter: 8.25″
- Hub Length: 4.00″
- Overall Diameter: 8.25″
- Maximum Speed: 3600 RPM
- Material: Steel
- Keyway: None (straight bore)
- Weight: Approximately 54 lbs (24.5 kg)
- Part Number: 0258641
- Series: Falk Steelflex T31/T35
- Bushing: None
Typical Applications
Grid couplings are ideal for pump drives, compressors, motors, fans, and industrial machinery requiring shock absorption and misalignment tolerance. The 1090T hub size accommodates mid-range torque applications in manufacturing, marine, and heavy equipment industries. RSB (rough stock) hubs are standard in retrofit and custom coupling assemblies where bore diameter must match the driven shaft.
Compatibility & Replacements
Compatible With
- Falk Steelflex 1090T coupling spacers and grids
- Falk T31 and T35 coupling halves
- Industrial electric motors and gear reducers with shaft diameters 1-1/16″ to 4″
- Pump and compressor drive shafts (industrial-duty applications)
Replaces / Drop-In Replacement For
Verify compatibility with your system integrator before ordering. This hub is a component part and must be paired with the correct coupling size and grid type for your application.
Works With
- Falk Steelflex grid couplings—T31/T35 series spacer-type designs
- Rexnord (formerly Falk) coupling grids and elastomer components
- Custom shaft alignment and installation using Falk LTG (Long Term Grease) lubrication
- Industrial power transmission systems up to 3600 RPM
