Aluminum vs Stainless

[retiredfornow]

As a general rule, on the same style/type/pitch of prop, will a aluminum prop produce the same RPM as a stainless one? The only thing that changes is the material. Thanks.

 

[steelespike]

Re: Aluminum vs Stainless

There is no cut and dried answer.Best I can do is aluminum would likely produce less rpm and
speed. Changing from one to the exact result becomes unpredictable.
Usually a ss prop will out perform al though not allways.The degree of change can be slight to very good.

 

[retiredfornow]

Re: Aluminum vs Stainless

Thanks steele, you da man. That's what I kinda thought, just wanted it confirmed.

 

[bruceb58]

Re: Aluminum vs Stainless

Since stainless steel props are thinner for the same strength, there is less drag on the stainless and you will get more RPM.

 

[tpenfield]

Re: Aluminum vs Stainless

As a general rule, on the same style/type/pitch of prop, will a aluminum prop produce the same RPM as a stainless one? The only thing that changes is the material. Thanks.

Aluminum is OK for lower horsepower engines, but the blades of an aluminum prop are much thicker than a stainless steel prop. The combination of blade thickness and higher horsepower results in excessive cavitation on the back of the blades of an aluminum prop, whereas the same prop in stainless steel will perform better.

 

[jimmbo]

Re: Aluminum vs Stainless

Since stainless steel props are thinner for the same strength, there is less drag on the stainless and you will get more RPM.

Since stainless weighs more it take more power to turn it so you might see a decrease in rpm. The Stainless blades being more effeicent, might retain a better grip on the water than the Aluminium blade. This too might lower rpm compared to the Aluninium if the Aluminium was cavitating

 

[bruceb58]

Re: Aluminum vs Stainless

Since stainless weighs more it take more power to turn it so you might see a decrease in rpm.

Not an issue as the rotating mass of the prop is insignificant compared to the water load.

 

[Bob_VT]

Re: Aluminum vs Stainless

This is what is stated in the iboats store http://boatpropellers.iboats.com/propeller-tutorials/material/?*******=664907211

 

[Texasmark]

Re: Aluminum vs Stainless

Not an issue as the rotating mass of the prop is insignificant compared to the water load.

Ditto

Additionally, most alum props are of general purpose design (Turning Point Hustler an exception but still alum with thick blades) and most SS props are of high performance design besides their inherent thin blades. So you don't have an apples to apples comparison.

Only way I would consider an alum prop is if I boated in the rocks.

My 2c.

Mark