When choosing a propeller for a boat, there are many reasons to opt for a stainless steel propeller. One of the most obvious motivations for selecting a stainless steel propeller is the added performance it provides the boat. Increased speed and power aid in reducing the time required to bring the boat up on plane. Propellers made of stainless steel have less rotating mass than other types of propellers, which equates to faster acceleration. Other benefits to using a well-balanced stainless steel propeller include improved fuel economy and a smoother ride.
The blades on a stainless steel propeller are much thinner than those found on an aluminum or composite-type propeller. The thinner blades are able to slice into the water much more effectively than the thicker blade designs. This means a much more effective propeller that drives the boat through the water with less power than the other blade designs. The stainless steel propeller blades are also machined with a much better-designed cup in the blade. The cupping of the blade allows the propeller to hold more water on the blade's surface, effectively driving the boat as if it had a much larger propeller in use.
Unlike an aluminum propeller that is easily broken if an underwater obstacle is encountered, a stainless steel propeller is more likely to be bent. This allows an experienced propeller repair service person to straighten the propeller and resharpen the edges. Many stainless steel propeller blades are sharpened to the point that they can actually cut through human skin. The purpose of sharpening the blades is to decrease the effort required to drive the edge of the blade through the water.
These added benefits do not come without cost, however. In most cases, a stainless steel propeller will cost nearly twice as much as a similar aluminum or composite propeller. The rate of theft of the stainless propeller is also much greater than that of other propeller types. After use, owners of vessels equipped with the expensive propellers often remove them at the boat ramp to prevent theft. Some outboard boat motors must be specially tuned for the performance-orientated propeller due to its ability to grab the water and bog the stock motor at the sudden application of throttle.