Determining the spline count on your boat propeller shaft is vital in choosing the correct propeller for your boat motor. What is a spline? These are the little teeth you see on both your propeller shaft and inside the hub of your propeller. To identify your spline count, simply count the teeth on your propeller shaft, or the teeth in your existing propeller hub.
Some boat motors have a "pin drive" propeller shaft, which means there are no splines on either the shaft or the propeller hub. For these applications, the propeller is secured to the smooth shaft using a pin through the shaft.
When choosing a propeller, always verify that you are selecting the correct number of splines for your boat motor.