This is a rigid metal coupling, 20mm long and 9mm in diameter, with a copper finish. It is secured with M3 grommets. Multiple bore combinations are available, suitable for connecting motors and drive shafts in small transmission systems for RC model boats, cars, robots, etc. Each coupling comes with grommets, and an installation wrench is included with every order.

Product Parameters

Material: Metal (copper finish)

Length: 20mm

Outer Diameter: 9mm

Fastening Method: Side M3 grommet screw

Bore Diameter Tolerance: +0.02 to 0.05mm

Package List

Metal Rigid Couplings × 4 (Bore Size of Your Choice)

M3 Mesh Screws × 16 (Pre-installed)

1.5mm Allen Wrench × 1 (per order)

Accessories: Each coupling includes a grommet screw; each order includes a 1.5mm Allen wrench

Bore Diameter Marking Explanation: 3mm-5mm indicates a 3mm bore diameter on one end and a 5mm bore diameter on the other end (3-5 and 5-3 are the same specification)

Product Features

Precision Fit: Bore diameter tolerance +0.02-0.05mm, ensuring a tight fit with the shaft.

Compact Size: 20×9mm compact design, suitable for space-constrained applications.

Copper Finish Metal surface treatment, aesthetically pleasing and durable.

Variable diameter connection: Multiple bore diameter combinations to fit shafts of different diameters.

Ready-to-use accessories: Screws and wrenches included, no need for additional purchases.

Wide versatility: 2-8mm bore diameter range, covering most micro motor shafts.

Precautions:

Coaxiality requirement: Rigid couplings cannot compensate for angular deviations; ensure both shafts are coaxial during installation.

Screw tightening: Tighten both screws evenly to avoid unilateral stress.

Anti-loosening check: Recheck screw tightness after 24 hours of operation.

Speed ​​limit: Recommended maximum speed ≤ 5000rpm.

Rust prevention and maintenance: The copper-colored surface treatment provides some rust prevention; however, care should still be taken in long-term humid environments.