Aluminum vs. Stainless Steel

Aluminum vs. Stainless Steel
The decision between purchasing an aluminum or stainless steel propeller can be difficult. However if you fully understand the differences between them, your decision can be much easier.

The most common understanding of the difference is that stainless steel propellers perform better than aluminum propellers. This is only half true. Material (Stainless vs Aluminum) only accounts for approximately 10% of the actual performance of the propeller. The other 90% of performance is in the blade design.

Well designed aluminum propellers will out perform an average stainless steel boat propeller. So it's important to research a propeller's performance before your purchase. It is also important to try different pitches and brands to get your boat dialed in to the best possible propeller.
The advantage of a stainless steel propeller over aluminum is durability. Stainless props can withstand more of the damage caused by small rocks, sand, or other loose objects in the water.

However, the disadvantage to a stainless propeller is that there is “minimal give" to the blades, so if you hit an object hard enough, there is a possibility of causing major damage to your lower unit is increased greatly. With aluminum props, the blades will most likely sacrifice themselves before any damage is caused to your lower unit.

If you run in deep or familiar waters, or in salt/brackish water, a stainless steel propeller can be a good choice. But it is important to always carry a spare propeller on board, and a spare aluminum is an inexpensive choice. Boat propellers are the least expensive way to upgrade the performance of your boat.