Overview
The Falk 20T31 shaft hub is a precision-engineered component designed for use with Falk Steelflex grid couplings. Manufactured by Rexnord (successor to The Falk Corporation), this hub accommodates a 1.25-inch (1-1/8″) shaft bore and delivers reliable torque transmission with integral flexibility. The full spacer design allows the coupling to absorb shock loads and dampen vibration while maintaining rigid axial support—ideal for connecting motors, pumps, and driven equipment in industrial machinery.
Key Features
- 1.25-inch (1-1/8″) shaft bore for standard industrial shafts
- Full spacer configuration with 3-1/2″ spacer length for proper hub gap alignment
- Tapered grid slots for secure grid engagement and torque transmission
- Compact 1.625-inch center dimension housing
- Setscrew mounting (part 908500) for positive shaft lock
- Durable steel construction rated for heavy industrial duty
Technical Specifications
- Shaft Bore Diameter: 1.25″ (1-1/8″)
- Hub Type: Shaft Hub for T31 Steelflex Coupling
- Spacer Length: 3-1/2″
- Center Dimension (Cl Dim): 1.625″
- Hub Length Through Bore: 1.38″
- Setscrew Axial Location: 1.08″
- Setscrew Part Number: 908500
- Weight: 580 grams (1.28 lbs)
- Coupling Size: 5 (small frame grid coupling)
- Mounting Style: Setscrew with tapered grid slot
- Operating Condition: New in Box
Typical Applications
The Falk 20T31 hub is widely used in:
- Centrifugal and positive displacement pump drives
- Electric motor-to-gearbox connections
- Turbine and engine-driven applications requiring flexible transmission
- Conveyor line shaft systems
- Industrial fan and blower assemblies
- General industrial power transmission requiring vibration damping
Compatibility & Replacements
Compatible With
- Falk Steelflex T31 Grid Couplings (all sizes accommodating 20T31 hubs)
- Rexnord Grid Coupling Systems (post-acquisition)
- Tapered grid flex couplings rated for up to 1,650,000 lb-in torque capacity
- Standard industrial shaft applications up to 1-1/8″ diameter
Replaces / Drop-In Replacement For
The Falk 20T31 is the original component for Falk Steelflex T31 full spacer couplings, size 5. Direct replacement for any worn or damaged shaft hub in this coupling series. Always verify coupling size and bore requirements before substitution.
Works With
- Falk Long Term Grease (LTG) lubricant for 5-year lubrication intervals
- Standard setscrew fasteners and hex keys for installation
- Falk grid coupling covers and elastomer grids in T31 series
- Motor soft-starters and variable frequency drives (VFDs) in flexible coupling applications
