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Description: These stainless steel shaft couplers allow you to couple two size shafts together. They can be used for connecting motor shafts to drive shafts, or two different-sized shafts. These shaft couplers have a length of 0.75”, a outer diameter of 0.42”, and couple 1/4” to 5mm shafts.

Actobotics is a robotics building system based around extruded aluminum channels, gears, precision shafts, and ball bearings. Thanks to the two standardized hole patterns, nearly all Actobotics components can be intuitively connected together. The wide range of components makes building complex electromechanical prototypes or finished projects a reality.


  • Length - 0.75”
  • Diameter - 0.42”
  • Bore A ID - 1/4”
  • Bore B ID - 5mm


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Customer Reviews

4.7 out of 5

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Good enough.

I’m using this to couple a stepper motor to ¼-20 threaded rod. Its the best thing I’ve tried so far, but I wouldn’t say I’m totally satisfied. The threaded rod is a bit under .25" in diameter, so there’s wobble in the rod when you tighten the single set screw against it.

A coupler with 3 set screws per side might stand a better chance at aligning the two shafts, bit I’ve tried that and at these diameters its super fiddly.

I ended up wrapping teflon tape (the white stuff for plumbing) around the threaded rod before securing it in this. It was better but not perfect.

All that said, a solid ¼" shaft would probably work great in this.

Just the ticket

I needed to couple the short shaft of a motor to a long threaded rod - the perfect solution.