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Three silver electroplated steel universal joint couplings 23mm long 9mm diameter with wrench and M3 screws

Unique-Bargains

Unique-Bargains 3mm to 3.17mm Universal Joint Coupling 23mm x 9mm Pack of 3

SKU CH-2WV3-G7PMJ

Pack of three 23 mm universal joints connect 3 mm and 3.17 mm shafts for RC models, 3D printers and DIY torque transmission

  • Connects 3 mm and 3.17 mm shafts for mixed-size torque transfer
  • Pack of three joints with wrench and M3×0.5 screws ready to install
  • 45# steel with electroplated finish resists wear and corrosion
  • Large transmission torque and stable rotation for reliable power delivery
  • Compact 23 mm length and 9 mm diameter fits tight RC and DIY spaces

Shaft Coupling for RC and DIY Projects

This pack supplies three universal joints that connect a 3 mm shaft to a 3.17 mm shaft so both rotate together and transmit torque. Each joint measures 23 mm long with a 9 mm outer diameter and uses M3 × 0.5 fastening screws. The couplings suit RC cars, RC boats, 3D printers, snow blowers, grinders and similar hobby builds.

Replaces Mismatched or Fixed Couplings

Swap these in when an existing rigid coupling cannot bridge the 3 mm to 3.17 mm size difference or when angular misalignment causes vibration. The rotatable joint handles the offset while delivering high torque transmission and low gap impact. The upgrade is worthwhile whenever the current link binds, slips or wears prematurely under load.

Check Shaft Diameters and Alignment Tolerance

Verify that the two shafts you intend to join measure 3 mm and 3.17 mm respectively, because the bores are not adjustable. Confirm the installation can stay within the maximum allowable eccentricity range, otherwise the joint will not transmit torque smoothly. Ensure you have a suitable hex key for the M3 × 0.5 screws before starting.

How it compares

Measured against everything we stock in Hose Fittings, Adapters & Clamps, at today’s prices. Recalculated every night.

Price $5.99
Cheaper than about 80% of the 2,955 comparable items (median $17.99).

Specifications

Product
Brand nameUnique Bargains

Questions about this item

Will the 9 mm outer diameter and 23 mm length fit inside my RC model's drivetrain space?

Each coupling measures 9 mm across and 23 mm long, so compare those dimensions with the available clearance in your chassis before ordering.

What is the correct order for tightening the M3×0.5 screws so the two halves stay aligned?

Slide each half onto its shaft first, bring the shafts into alignment, then tighten the M3×0.5 set screws evenly with the supplied wrench to lock the joint without binding.

How often should I inspect the 45# steel universal joints for wear in a high-torque 3D printer axis?

Check for play or corrosion on the electroplated surfaces every few months; replace any joint that shows excessive backlash or pitting to maintain precise motion.

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