Blog posts of '2023' 'June'

Different types of boat propellers
An informative article about the different types of boat propellers and marine engines.
The Many Advantages of a Stainless Steel Propeller

Outdoor activities have increased during the COVID pandemic. And, like a lot of recreational equipment, boat sales have exploded.

There are a lot of decisions to make when buying a boat. And people spend thousands of dollars every year upgrading their engine and components to increase their craft’s performance. But one of the easiest and most cost-effective ways to do so is by selecting the right propeller.

There are several characteristics to consider when choosing a new propeller or upgrading an old one. The most important one is the material used to construct it. A stainless steel propeller can increase performance and last a lifetime.

Keep reading to find out more about the many advantages of a steel prop and why it might be the right choice for your boat.

Propeller Basics

When selecting a propeller for your boat, there are three main things to consider:

  • the number of blades
  • the diameter and pitch
  • the material

Each of these has a lot to do with how your boat handles and performs, as well as how fuel-efficient it is. Let's take a look at each one in more detail.

Blade Number

Propellers come with between three and five blades. Five-blade props are usually reserved for very heavy vessels. Since they have the largest surface area, they require more power to turn, which eats up more fuel.

Three-blade propellers are the most popular since they combine speed with fuel efficiency. This is because they have less surface area and need less power to turn. While there is still some debate about this, three-blade props are generally known to run faster than ones with more blades.

Some people prefer four-blade propellers for their increased “grip” and handling. They can offer a smoother ride and steadier cruising speeds, as well as the potential for greater acceleration. But again, having more blades increases drag, which requires more horsepower and fuel consumption.

Diameter and Pitch

The diameter of a propeller is basically the width of the circle made by the blades. The size of the blades determines how much water they can push per rotation.

A propeller’s blades are designed much like the thread of a screw. The pitch is the amount the prop moves forward in one rotation. Pitch is very important because it determines the gear ratio between the boat’s engine and the water.

For optimum performance, you want your boat to operate within its wide-open throttle (WOT), which you should be able to find in the engine owner’s manual. If a propeller pitch is too low, the engine could run over its WOT and risk damage. If the pitch is too high, the engine will run far below its WOT, which also can strain its gears and components.

You will often find diameter and pitch indicated on the propeller, with diameter listed first. For instance, a 14" x 19" prop would be 14 inches in diameter and have a pitch of 19 inches.

Material: Stainless Steel vs Aluminum Propeller

Most boat propellers are made of either aluminum or steel. Aluminum is the most popular propeller material used today, partly because it is very affordable.

But stainless steel propellers, while more expensive, offer many advantages. Consider just a few.


Both aluminum and steel propellers are resistant to rust and corrosion. And aluminum propellers are very durable under regular usage and conditions.

But steel is much stronger than aluminum. It is an alloy of iron, with carbon and chromium added in to improve strength and make it less likely to fracture. Stainless steel props are not brittle like many low-end aluminum ones.

Steel props are much less likely to bend or break when striking underwater debris, like logs or sandy bottoms. And they are more likely to last longer than aluminum ones, even with regular use.


Another advantage associated with steel’s strength is its lack of pliability. Steel props will not flex like aluminum ones, even under the strain of heavy loads.

Less bend means more power is being transferred in propulsion, which means greater acceleration and maneuverability. This can be beneficial to any boater, but especially those pulling people on skis or other recreational equipment.

Aluminum propellers tend to be much thicker than stainless steel ones, in order to compensate for the deficit in strength. This increases drag and also diminishes performance.

Steel propellers are much more common on boats designed for saltwater. This is because of their ability to handle the power of bigger engines needed in the ocean.


One area where aluminum propellers edge out steel ones is the initial cost. Stainless steel propellers tend to be more expensive than aluminum ones, which can sometimes be found for under $100.

Steel propellers also are more difficult to repair if broken. But, while aluminum props are cheaper to fix, the repair cost can still come close to the price of a new propeller. This is less so the case with stainless steel, which negates the advantage of aluminum in this regard.

In short, a steel propeller’s longer lifespan and resistance to breaking can still make it a better bargain, even if you consider the difference in repair costs.

Find the Right Stainless Steel Propeller for Your Boat

Now that you have an idea of the many advantages of a stainless steel propeller, you can begin shopping for one that is right for your boating needs. It can increase performance and efficiency while lasting a lifetime.

Deep Blue Yacht Supply was founded on the basic principle of ensuring our customers get the right product for their boating needs. Our staff has over 100 years in the marine propulsion industry and can help you select the best stainless steel propeller for your boat.

We carry a variety of steel propellers, accessories, and other boating hardware. And we will ship our products to almost any location worldwide!

Outboard Motor Props 101

An informative article on Outboard Motors and the propellers that make them go.

Stainless Steel vs Aluminum Prop: What's The Difference?

An informative article on stainless steel vs. aluminum boat props.

SOLAS Propellers: What You Need to Know
A SOLAS propeller is well-know for its quality. Check out this useful guide to get a better idea if this is the right choice for your needs.