Brass Coupler (3-4mm)

The Brass Coupler (3-4mm) is a small rigid shaft coupler made of brass that connects a 3 mm shaft to a 4 mm shaft. It is a quick way to join a motor to an axle, lead rod, wheel or gear when the two shaft sizes do not match, and screws on each side clamp the shafts in place. It suits RC models, small robots and DIY mechanisms.

Brass Coupler (3-4mm) Specifications

• Material: brass
• Bore sizes: 3 mm on one end, 4 mm on the other
• Type: rigid shaft coupler
• Fixing: screws tighten onto each shaft
• Quantity: 1 coupler

Brass Coupler (3-4mm) Applications

• Connecting a 3 mm motor shaft to a 4 mm axle or drive shaft
• Drive trains in RC boats, cars and models
• Fitting wheels, pulleys or gears made for a 4 mm shaft to a small motor
• Robotics and DIY mechanisms

What's in the Box

• 1 × brass coupler, 3 mm to 4 mm

Tip: Rigid couplers need the two shafts to be well aligned, otherwise the motor bearings wear and the drive vibrates; switch to a flexible coupler if alignment is difficult. Tighten the screws onto the flat of the shaft if there is one, and use a drop of thread locker where there is a lot of vibration.

Orders placed before 14:00 are ready for pickup the same day. Delivery across Lebanon usually takes 1–3 working days.