How do I know a prop is Stainless steel

Rick.

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Hello All. This is my first post in the prop forum. I found a prop for sale and the Kijiji add says it's new and stainless steel. It is painted black in his picture. I always thought a stainless prop would be unpainted but I don't know that. Is there a way to tell what material it is made of without doing any cosmetic damage to it? Thanks for your help. Rick.
 

coastalrichard

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Re: How do I know a prop is Stainless steel

If a magnet sticks to it, it's stainless. Magnets won't stick to aluminum.
 

H20Rat

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Re: How do I know a prop is Stainless steel

If a magnet sticks to it, it's stainless. Magnets won't stick to aluminum.

Guess I haven't checked, but most stainless steel is nonmagnetic. SS that has a high nickel/chrome content, as you would want for something that is going to be in the water, is generally non-magnetic.

In other words, if the magnet sticks, it is certainly not aluminum! If it does not stick, it doesn't tell you anything about the prop. Could be aluminum, or non magnetic SS.

Without doing further testing, one way to tell is to look at the blade thickness. SS are usually a little thinner. Also, there should be some model stamps somewhere on the hub which should lead you to what it is.
 

Scott Danforth

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Re: How do I know a prop is Stainless steel

stainless steel is 2.8 times heavier than aluminum. many stainless props are powder coated because it is cheaper than polishing.
 

coastalrichard

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Re: How do I know a prop is Stainless steel

Well...I grabbed one of the many magnets off the fridge...it doesn't stick to my utility trailer or prop (both aluminum) but it does stick to my gas cap and several other known stainless fittings on the boat.

Smokin, could it be that some grades of stainless have enough steel to remain magnetic while others won't (the boys at the junk yard swear by this method!)?
 

spdracr39

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Re: How do I know a prop is Stainless steel

Well...I grabbed one of the many magnets off the fridge...it doesn't stick to my utility trailer or prop (both aluminum) but it does stick to my gas cap and several other known stainless fittings on the boat.

Smokin, could it be that some grades of stainless have enough steel to remain magnetic while others won't (the boys at the junk yard swear by this method!)?

400 series stainless is magnetic and is used in cheap applications like inexpensive "stainless" gas grills, car trim, restaurant equipment... it has very little nickel content. 300 series stainless is non-magnetic and has a higher nickel content and will last longer, costs more, and is not magnetic. Since I work at a recycling facility I always carry my magnet with me and don't pay extra for the stainless claim unless it is non magnetic.
 

QC

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Re: How do I know a prop is Stainless steel

Best way to verify might be the part number? Agree weight is VERY obvious with Stainless props. Some are unbelievably heavy.
 

tswiczko

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Re: How do I know a prop is Stainless steel

Well...I grabbed one of the many magnets off the fridge...it doesn't stick to my utility trailer or prop (both aluminum) but it does stick to my gas cap and several other known stainless fittings on the boat.

Smokin, could it be that some grades of stainless have enough steel to remain magnetic while others won't (the boys at the junk yard swear by this method!)?
There are 3 types of Stainless Ferritic, Austenitic and Martensitic, and more than one grade of each of the different types.
http://www.mceproducts.com/knowledge-base/article/article-dtl.asp?id=18
 

spdracr39

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Re: How do I know a prop is Stainless steel

If you grind it and it sparks its either stainless or steel of some type. If there is no spark its aluminum or brass. Not a practical test however.
 

Rick.

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Re: How do I know a prop is Stainless steel

Wow. Ask a simple question and....LOL. Certainly appreciate your help. I do have a part number the fellow gave me. it is#386841 which and it is for a 1995-40 HP Johnson. Can you tell from that if it is stainless. I live about 50 miles from the seller so don't want any surprises. Thanks, Rick.
 

haulnazz15

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Re: How do I know a prop is Stainless steel

You would need to know the prop manufacturer most likely. Like Michigan Wheel, Solas, etc.
 

82rude

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Re: How do I know a prop is Stainless steel

if your thinking about going to look at the prop the simple solution is to take your old prop .one in each hand will tell the diff as stainless props are fairly heavy,also lots of people paint their ss props as a anti theft thing.
 

Brewman61

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Re: How do I know a prop is Stainless steel

My SS prop (Power Tech) does hold a magnet. It's also way heavier than my AL prop.
 

colbyt

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Re: How do I know a prop is Stainless steel

I don't know the different grades and I for sure have no clue of which a prop is made. Food service grade and my fridge door will not hold a magnet. Some of the lessor metals that pass for SS are magnetically inclined.
 

jestor68

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Re: How do I know a prop is Stainless steel

Older OMC SS props that I purchased back in the day were painted black. The aluminum props were white.
 

spdracr39

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Re: How do I know a prop is Stainless steel

Wow. Ask a simple question and....LOL. Certainly appreciate your help. I do have a part number the fellow gave me. it is#386841 which and it is for a 1995-40 HP Johnson. Can you tell from that if it is stainless. I live about 50 miles from the seller so don't want any surprises. Thanks, Rick.

11-3/4 x 17 RH Alum. made by Michigan wheel
http://www.shipstore.com/SS/HTML/mwc/mwc012039.html
Google is our friend
 

catfishr1

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Re: How do I know a prop is Stainless steel

Howdy Rick. S/S props are manufactured by pouring molten stainless into a mold thus 1 fluid piece. If you look at back side of prop you can see seam were blades are attached on aluminum.
 

Rick.

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Jul 30, 2006
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Re: How do I know a prop is Stainless steel

Well it was aluminum. When I pointed that out to him he said I could have it for 40 dollars so I bought it. It is new, never used and an exact match to the one I had brought with me. Thanks to all who replied. Much appreciated. Rick.
 
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