How To Choose The Right Shaft Coupling for Your Machine

1Why Couplings Matter

A coupling is a mechanical component that connects two shafts — the driving shaft and the driven shaft — to transmit torque. In high-speed rotation and heavy-load operation, shaft misalignment (radial displacement, axial deviation, or angular misalignment) is almost always present.

A well-designed coupling solves three core problems:

Misalignment compensationAbsorbs minor installation and operational errors, protecting bearings from premature wear and damage.
Vibration and shock absorptionReduces mechanical shock and noise, extending overall equipment life.
Backlash-free transmissionEnsures precise synchronization in servo systems for accurate, repeatable motion control.

2The Complete ShangGong Coupling Range

Our coupling line spans SG1 to SG19, covering a wide range of shaft diameters, torque levels, and installation spaces to suit nearly any application.

Wide selection range

Outer diameters from 19 mm to 200 mm
Rated torque from 1 N·m to 4000 N·m
From micro servo systems to heavy-duty transmission systems

Flexible installation compatibility

Clamping-type, set-screw-type, and keyway-type shaft connections
Custom bore sizes available to match different motor shafts

Complete structural coverage

Diaphragm, jaw, bellows, cross-slider, and rigid types
Solutions engineered for high rigidity, high damping, or high misalignment compensation

Stable materials and manufacturing

Aluminum alloy and stainless steel bodies
Precision CNC machining and dynamic balancing for consistent quality in mass production

3Choosing by Application: Four Representative Series

Every application is different. Here is how our main series map to real-world needs.

SG3

Cross Slider Coupling

Simple cross-slider structure that allows relatively large radial and angular misalignment while maintaining zero backlash, high torsional rigidity, and high sensitivity. The aluminum alloy body offers oil resistance and electrical insulation; fixed with clamping screws.

Best for: general transmission systems · high misalignment compensation · oil-exposed environments · applications requiring electrical insulation

SG5

Bellows Coupling with Expansion Sleeve

Bellows structure with expansion-sleeve connection delivering high clamping force and high torsional rigidity. The flexible stainless steel bellows compensates radial, angular, and axial misalignment, with identical rotational performance in both directions. Alloy steel body, stainless steel bellows.

Bellows-type flexible coupling — stainless steel bellows, zero backlash

Best for: high-torque transmission · servo motor and ball screw connections · significant installation misalignment · precision automation equipment

SG10

Elastomer Coupling

Central elastomer element absorbs vibration and dampens shock loads while compensating radial, angular, and axial misalignment. Offers oil resistance and electrical insulation with identical performance in both rotation directions. Aluminum alloy body with TPU insert.

Best for: pumps · fans and blowers · automated conveying systems · medium-to-high-speed general transmission

SG15

Multi-Section Expansion Sleeve Diaphragm Coupling

Diaphragm coupling with expansion-sleeve connection offering zero backlash, easy installation, and high torque transmission. Stainless steel diaphragm compensates angular and axial misalignment; alloy steel body.

Best for: large CNC machining centers · heavy-duty automated production lines · high-torque servo systems · heavy industrial machinery requiring high rigidity

4Where ShangGong Couplings Are Used

Our couplings are widely applied across CNC machinery, electronics manufacturing, new energy equipment, servo and stepper systems, ball screws, packaging and conveying lines, pumps, and fans — anywhere precise, reliable power transmission is non-negotiable.

5Customization and OEM

Bore dimensions can be customized to match your motor shafts. Beyond standard models, we support custom materials, finishes, and OEM/ODM production, so you get a coupling built around your machine — not the other way around.

Choose the Right Coupling for Reliable Transmission

The right coupling means stable transmission performance, higher precision, and longer equipment life. From selection guidance to custom design, the ShangGong team provides reliable power transmission solutions for a wide range of industrial automation applications.

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