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When misalignment, vibration, or shaft slippage disrupts your CNC build or motor-driven project, the root cause is often a poorly fitted coupler. Engineers, makers, and machine builders who demand repeatable accuracy need a shaft coupler that locks firmly, transmits torque without flex loss, and fits a wide range of bore diameters without custom machining.
This rigid shaft flexible coupling is machined from aluminum alloy with a hard-anodized surface, available in single-joint and double-joint configurations. Coupler outer diameters range from D20mm to D94mm (approx. 0.79"–3.70"), with bore diameter compatibility spanning 4mm to 50mm (approx. 0.16"–1.97"). The helical-cut body provides a degree of angular compensation while maintaining rigid axial torque transmission.
Typical applications include CNC router Z-axis motor coupling, 3D printer lead screw to stepper motor connection, benchtop lathe spindle shaft joining, and servo motor shaft coupler replacement in automation rigs — all scenarios where a reliable motor shaft joint coupler connector is critical to machine performance.
Choose single-body for compact motor bays or double-joint for extended shaft spans and greater angular compensation between two shafts.
Covers the most common stepper and servo motor shaft diameters, eliminating the need for custom adapters across NEMA 17 to NEMA 34 builds.
Lightweight yet rigid construction resists corrosion and wear, maintaining dimensional stability under continuous rotational load.
The spiral cut allows minor angular and parallel misalignment compensation without sacrificing axial rigidity or introducing backlash into the drivetrain.
Dual set screws per bore end provide secure shaft locking, preventing rotational slip under high-torque or reversing-direction motor loads.
From D20×L20mm up to D94×L68mm (single) and D94×L98mm (double), with matching bore options — one listing covers your entire machine build.
| Material | Aluminum alloy (hard-anodized) |
|---|---|
| Configuration | Single joint / Double joint (see variant options) |
| Outer Diameter (D) | 20mm – 94mm (0.79" – 3.70") |
| Body Length (L) | 20mm – 98mm (0.79" – 3.86") |
| Bore Diameter Range | 4mm – 50mm (0.16" – 1.97") |
| Clamping Method | Set screw (dual per bore end) |
| Finish | Hard anodized (corrosion resistant) |
| Quantity per Order | 1 pc |
| Weight | See variant options |
| Compatible Motor Types | Stepper motors, servo motors, DC motors |
| Typical Applications | CNC routers, 3D printers, lathes, automation rigs |
Single-joint couplings are more compact and suited for tight motor bays where shaft ends are close together. Double-joint couplings are longer, providing greater angular misalignment compensation and are ideal when the motor and driven shaft are spaced further apart or when additional flexibility is needed in the drivetrain.
Match the bore diameter to your motor shaft diameter. Common NEMA 17 shafts are 5mm; NEMA 23 shafts are typically 6.35mm or 8mm; NEMA 34 shafts are commonly 12.7mm or 14mm. Select the bore range option that includes your shaft size — for example, "5mm to 12mm" covers NEMA 17 and smaller NEMA 23 shafts.
Yes. The helical-cut flexible body allows for minor angular misalignment (typically up to 1°–3°) and small amounts of parallel offset. However, this is a rigid-type flexible coupling — it is not designed for large misalignment. For best results, align shafts as closely as possible before installation.
The hard-anodized aluminum alloy surface provides good resistance to oxidation and mild corrosion. It is suitable for indoor workshop environments and light-duty outdoor use. For highly corrosive or wet environments, additional protective measures are recommended.
Dual set screws per bore end provide a secure mechanical lock on the shaft. For high-torque or frequent direction-reversing applications, ensure set screws are tightened to the appropriate torque spec and consider using a thread-locking compound for added security.
The D value is the outer diameter of the coupler body and the L value is the total body length. Larger D and L dimensions generally support larger bore diameters and higher torque capacity. Select the smallest coupler size that accommodates your shaft diameters to keep the assembly compact and minimize rotational inertia.
Yes. This is one of the most common use cases. The D20mm x L20mm (single) or D20mm x L28mm (double) options with 4mm–8mm bore are well-suited for connecting a 5mm stepper shaft to a standard T8 or T12 lead screw on most FDM 3D printers.
