When propellers made of composite, or plastic, first came on the market over 20 years ago, I was very skeptical that they could match an aluminum prop in strength and performance. Today, while not all composites are created equal, a couple of manufacturers use space age composites to exceed the strength of the old traditional props. One uses a long-fiber nylon and carbon composite to deliver outstanding strength and performance. I suppose this should not surprise us as many commercial turbo-prop (propeller powered by a jet engine) aircraft now use composite props and ‘Formula I’ race plane rules specify composite props over aluminum, because “aluminum props are subject to catastrophic failure.”
So far, composite manufacturers have held their prices down to about the same as aluminum, making them an excellent value.
My pick of the composites is a prop called “Piranha.” This is not simply due to superior performance, but because the hub is guaranteed for life and you can easily and inexpensively replace individual blades should you break one. Applications range from six to 300 horsepower.