Understanding Propeller Sizes

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If you would like to narrow your search through our range of Props it's important to have a basic understanding of your propeller.



Bore (Shaft Diameter): The bore of the propeller is specific to the prop shaft that is on your boat. Shaft size is not interchangeable, you must use the correct size prop for your boat’s shaft, or the prop will not fit. The bore of your shaft will either be SPLINED or Tapered with a Keyway as pictured left.




Rotation: Like bore, rotation is specific to the power train of the boat; if your boat needs a left-hand rotation propeller, you must use a left-hand rotation propeller.

Diameter: In general, a larger diameter means more surface area, which means better transmission of power from the engine to the water. Typically, the diameter is limited by clearance around the prop, which is especially important to check.



Cup: Is the curvature of the blade at its edge, primarily translates to the amount of load the prop will put on the motor.

Pitch: Is the distance the prop would travel after making one full revolution. A lower numerical pitch number means higher engine RPMs relative to boat speed, which translates to better performance for slower speed activities.


Still not sure the right Prop for your boat?

Please Contact Us directly and we can discuss the right prop for your boat.  Phone: +61 411 301 521 | Email: info@ojpropsint.com