When choosing from among the available propeller options, comparing and contrasting the front-running metals has often been a matter of opinion. In many circles, it is simply taken as a commonly accepted belief that stainless steel is the preferred option. In truth, there are several noteworthy facts that support the choice of an aluminum boat propeller over stainless steel in many cases. It all distills down to understanding the differences, and making the best selection to suit the applicable circumstances.
First, the prop material only contributes a small percentage to the overall performance of the propeller. The majority of performance, which in many cases means a full 90% of that torque, can actually be attributed to the design of the blade rather than the choice of metal.
Researching performance provides significant advantages to the buyer, prior to making a purchase decision. This way, assessments regarding functionality and speed can be considered and weighed. Once the blade design preference is identified, then the determination between aluminum and steel can be considered.
While steel can offer some advantages in terms of durability, this is primarily relevant when a boat will be navigating shallow or obstacle-ridden waters. For example, stainless steel blades can withstand more harsh blows against rocks or other unidentified objects than many aluminum blades can.
On the other hand, aluminum is more pliable. The extraordinarily rigid characteristics of steel cause it not to bend or break when a large object is hit. This means that, when that steel propeller hits a foreign object hard enough, there is a greater opportunity that the boat will sustain damage to the entire lower unit. Although an aluminum propeller may result in a blade being sacrificed, that replacement cost will be far less inexpensive, as compared to the severity of the large-scale damage.
There are many advantages and benefits of using an aluminum boat propeller, if the conditions of the water and the surroundings enable its effective use. In addition, any boat captain who anticipates occasional encounters with either shallows or unexpected hazards can easily keep an inexpensive aluminum propeller available as a replacement.