GBC7 Series Setscrew Type Rigid Coupling
The GBC7 Series Setscrew Type Rigid Coupling is a precision micro rigid coupling available in aluminium alloy and stainless steel. Featuring setscrew fixation, ultra-low inertia, and bore sizes from 3 mm to 20 mm, it suits servo motors, CNC equipment, robotics, and instrumentation where zero-backlash torque transmission at speeds up to 23,000 rpm is required.
GBC7 Series Setscrew Type Rigid Coupling — Precision Micro Shaft Connector for High-Speed Applications
The GBC7 Series Setscrew Type Rigid Coupling is a compact, high-precision micro shaft coupling engineered for demanding motion control environments. With bore diameters from 3 mm to 20 mm and outside diameters from 16 mm to 40 mm, this series delivers zero-backlash torque transmission across robotics, CNC equipment, servo motor systems, optical instruments, and medical automation. Available in both aluminium alloy (standard GBC7) and stainless steel (SGBC7) variants. Explore our full range of rigid couplings or browse all coupling solutions.
Key Features
- Ultra-low moment of inertia for lightning-fast servo response
- Setscrew fixation mechanism ensures secure shaft engagement without bore deformation
- Two material options: lightweight aluminium alloy and corrosion-resistant stainless steel
- Wide bore range: 3, 4, 5, 6, 8, 10, 11, 12, 14, 15, 16, 18, 19, 20 mm
- Maximum rotational speed up to 23,000 rpm (GBC7-16 model)
- Zero backlash rigid torque path ideal for precision positioning systems
- Compact cylindrical profile minimises radial envelope requirements
Dimensions & Specifications
Dimensional Table — GBC7 (Aluminium) & SGBC7 (Stainless Steel)
| Model | Bore d1/d2 (mm) | ΦD (mm) | L (mm) | L1 (mm) | M | Wrench Torque (N·m) |
|---|---|---|---|---|---|---|
| GBC7-16 | 3 4 5 6 | 16 | 24 | 6 | M3 | 0.7 |
| GBC7-20 | 5 6 8 10 | 20 | 30 | 7 | M3 | 0.7 |
| GBC7-25 | 8 10 11 12 | 25 | 36 | 9 | M4 | 1.7 |
| GBC7-32 | 12 14 15 16 | 32 | 41 | 10 | M4 | 1.7 |
| GBC7-40 | 14 16 18 19 20 | 40 | 50 | 12 | M5 | 1.7 |
| SGBC7-16 | 3 4 5 6 | 16 | 24 | 6 | M3 | 0.7 |
| SGBC7-20 | 5 6 8 10 | 20 | 30 | 7 | M3 | 0.7 |
| SGBC7-25 | 8 10 11 12 | 25 | 38 | 9 | M4 | 1.7 |
| SGBC7-32 | 12 14 15 16 | 32 | 41 | 10 | M4 | 1.7 |
| SGBC7-40 | 14 16 18 19 20 | 40 | 50 | 12 | M5 | 1.7 |
Performance Specifications
| Model | Rated Torque (N·m) | Max Torque (N·m) | Max Speed (rpm) | Moment of Inertia (kg·m²) | Mass (g) |
|---|---|---|---|---|---|
| GBC7-16 | 0.3 | 0.6 | 23,000 | 3.1 × 10⁻&sup7; | 11 |
| GBC7-20 | 0.5 | 1 | 18,000 | 8.5 × 10⁻&sup7; | 20 |
| GBC7-25 | 1 | 2 | 14,000 | 2.6 × 10⁻⁶ | 39 |
| GBC7-32 | 2 | 4 | 10,000 | 9.1 × 10⁻⁶ | 71 |
| GBC7-40 | 5 | 10 | 8,000 | 9.1 × 10⁻⁶ | 100 |
| SGBC7-16 | 0.3 | 0.6 | 23,000 | 8.1 × 10⁻&sup7; | 28 |
| SGBC7-20 | 0.5 | 1 | 18,000 | 2.2 × 10⁻⁶ | 54 |
| SGBC7-25 | 1 | 2 | 14,000 | 7.1 × 10⁻⁶ | 100 |
| SGBC7-32 | 2 | 4 | 10,000 | 2.4 × 10⁻⁶ | 190 |
| SGBC7-40 | 5 | 10 | 8,000 | 2.4 × 10⁻⁶ | 210 |
Moment of inertia and mass figures are based on the maximum shaft bores.
How to Order — Part Number Guide
The GBC7 part number follows this structure: [S]GBC7-[OD]-[d1][d2]
- No S prefix = Standard aluminium alloy body
- S prefix = Stainless steel body (e.g., SGBC7)
- OD = Outside diameter in mm (16, 20, 25, 32, or 40)
- d1/d2 = Bore diameters in mm at each end
Example: GBC7-16-0406 = Aluminium alloy, OD 16 mm, d1 bore 4 mm, d2 bore 6 mm.
Typical Applications
Servo Motor & Stepper Motor Coupling
The GBC7 setscrew rigid coupling directly joins servo and stepper motor shafts to encoder or lead screw shafts, maintaining angular accuracy throughout high-speed cycles without backlash.
Optical & Scientific Instrumentation
Its micro footprint and minimal mass make it ideal for precision rotary stages, goniometers, and spectrometer actuators where added rotational inertia degrades measurement accuracy.
Medical & Laboratory Automation
The stainless SGBC7 variant is suited to liquid-handling robots, centrifuge drive systems, and diagnostic equipment where hygiene and corrosion resistance are mandatory.
CNC & Industrial Robotics
At speeds up to 23,000 rpm, the GBC7-16 supports high-RPM spindle motor connections and robotic joint actuators where speed stability and positional repeatability are paramount.
Our Manufacturing Facility
Every GBC7 Series coupling is manufactured on precision CNC machining centres with tight dimensional tolerances. Our quality management processes encompass incoming material verification, in-process dimensional inspection, surface finish assessment, and final functional testing before despatch. This rigorous approach guarantees that each coupling meets or exceeds its published torque and speed specifications.
Customer Reviews & Case Studies
★★★★★
Australia — Robotics & Automation OEM
We integrated the GBC7-20 into our pick-and-place robot arm servo drives. After 12 months of continuous three-shift operation, there has been zero shaft slip and positional repeatability has remained within 0.01 mm. An outstanding coupling for micro-robotics builds.
★★★★★
Germany — Optical Instrument Manufacturer
We specified the SGBC7-16 stainless coupling for a precision rotary stage operating at 18,000 rpm. The ultra-low inertia was critical for fast indexing speeds our spectrometer required. Delivery was prompt and dimensional accuracy was spot-on.
★★★★☆
United States — Medical Device Assembly
We switched to SGBC7-25 stainless couplings for our liquid-handling robot. Corrosion resistance is excellent in a frequent washdown environment. We requested a custom bore combination and the technical team was responsive throughout.
★★★★★
Japan — CNC Spindle Equipment
The GBC7-40 was selected for a high-speed spindle encoder coupling running at 8,000 rpm. Torque transmission has been flawless at rated load. We appreciate the consistent quality from batch to batch, which simplifies our incoming inspection process.
Frequently Asked Questions
What is the difference between GBC7 aluminium and SGBC7 stainless steel?
GBC7 aluminium alloy bodies offer significantly lower mass and moment of inertia, making them ideal for high-speed servo applications where rapid acceleration is required. SGBC7 stainless steel bodies provide superior corrosion resistance suited to washdown, food processing, and laboratory environments exposed to chemicals or moisture.
Can I order a GBC7 coupling with different bore diameters on each end?
Yes. The GBC7 series is specifically designed to accommodate mismatched bore combinations on either end within the available bore range for each outside diameter size. For example, a GBC7-16 can be supplied with d1 bore 4 mm and d2 bore 6 mm to connect shafts of different diameters.
What is the maximum operating speed for the GBC7 Series?
The GBC7-16 achieves the highest maximum rotational speed of 23,000 rpm. As outside diameter increases, the rated speed reduces: GBC7-20 at 18,000 rpm, GBC7-25 at 14,000 rpm, GBC7-32 at 10,000 rpm, and GBC7-40 at 8,000 rpm. These figures apply to both aluminium and stainless steel variants.
Will the setscrew damage my motor shaft?
Setscrew fixation may create minor surface indentations on polished or hardened shafts when tightened to the specified wrench torque. This is generally acceptable in most industrial and automation applications. Where a shaft must remain unmarked for reuse, the GBC7C clamp-type coupling is the recommended alternative.
Are custom bore sizes or special materials available?
Yes. Custom bore diameter combinations within each model size range are available on request. Our engineering team can discuss special material requirements, surface treatments, or dimensional modifications. Please submit a technical enquiry with your specifications.
Ready to Source the GBC7 Setscrew Rigid Coupling?
We supply GBC7 and SGBC7 setscrew rigid couplings to OEMs, system integrators, and distributors across Australia, Asia-Pacific, Europe, and North America. Whether you require standard stock models or custom bore configurations, our team is ready to support your procurement and engineering needs.
The GBC7 Series Setscrew Type Rigid Coupling is a precision micro rigid coupling available in aluminium alloy and stainless steel. Featuring setscrew fixation, ultra-low inertia, and bore sizes from 3 mm to 20 mm, it suits servo motors, CNC equipment, robotics, and instrumentation where zero-backlash torque transmission at speeds up to 23,000 rpm is required.
