316 Ss

Discussion in 'Materials' started by eyschulman, Feb 20, 2014.

  1. eyschulman
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    eyschulman Senior Member

    would good quality 316 stainless steel attract a magnet?
     
  2. Mr Efficiency
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    Mr Efficiency Senior Member

    After running a magnet over a few bits and pieces of which some are 304 and others 316, but I'm not 100% which are which, none attach to a magnet, if there is an attraction it is imperceptible.
     
  3. gonzo
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    gonzo Senior Member

  4. PAR
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    PAR Yacht Designer/Builder

    If it's 316, a good rare earth magnet will show some attraction, but not like it would if it was mild steel. A cheap magnet will show no attraction. In fact it's this very trick I use when buying stainless, I bring a cheap magnet along and see what "bites" as I fish in a drawer. 304 is much more magnetic than 316, though still not nearly as much as mild steel, a cheap magnet will show some attraction.
     
  5. Mr Efficiency
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    Mr Efficiency Senior Member

    Oh well, either my magnet is a bit tired, or all the stuff I tested with it is 316, I could not get the magnet to drag any of it, but it certainly was attracted to ordinary steel.
     
  6. PAR
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    PAR Yacht Designer/Builder

    Go get a good rare earth magnet and watch what happens.
     
  7. Mr Efficiency
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    Mr Efficiency Senior Member

    I am wondering what the reason for the original question is.
     
  8. michael pierzga
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    michael pierzga Senior Member

    Dont know.

    I cant make a piece of 316 stick to a rare earth magnet , but I can move the piece on a glass table with a rare earth magnet .

    You would need to ask a scientist for clarification
     
  9. PAR
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    PAR Yacht Designer/Builder

    I didn't say there would be much attraction, just that there would be some, certainly enough to feel or observe, as you moved the magnet. You don't need a scientist for empirical observation.
     
  10. eyschulman
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    eyschulman Senior Member

    Reason for question about 316 SS and magnetic character is I have ports that are rusting at a much higher rate than would be expected from quality 316 SS and they do attract a magnet taken from an electric tooth brush guts. I am trying to track down the cause.
     

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  11. alan white
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    alan white Senior Member

    It's probable that China is involved. Because stainless steel looks similar no matter whether 303, 304, 316, etc., importers who resell parts from Pacific rim countries, especially but not limited to China, are not as discriminating as they should be. They may be ignorent of such issues, which is irresponsible, or they may indeed know (based on complaints) that there is a problem, which is plainly dishonest. If no particular type of stainless was advertised, they are still responsible, though more responsibility rests on the consumer to be educated about what specs are desirable for normal use, etc..
    This kind of thing happens all the time. Especially polished 316 stainless ought to remain stain and rust free for a long time and should be easily repolished without a lot of work.
    My suggestion is you see what was advertised when you bought the ports. Was a particular type of metal promised? If so, there must be labs that do this sort of testing all the time.
    That pitting, if caused by normal sea air, is an indication of a stainless more suited to restaurant equipment, which don't usually rust because of a coating of grease. It may even be a 400 series, which rusts like nobody's business.
    Depending on size, I see simlar ports advertised for around $350-$500.00 a pop. If you paid that much, I think you were cheated.
    Impurities can also exist in cheaply produced metals, even if they are the correct alloy. Can you make this a warranty issue?
     
  12. pdwiley
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    pdwiley Senior Member

    Those rust pits are certainly not what I would expect from 316 stainless steel. In fact it looks like rust pits through chrome plating in the photo far more than it looks like rust pits in stainless.

    Time to talk to the supplier and possibly find someone with test equipment. A lot of scrap yards have a fancy gun that can tell what material is what.

    PDW
     
  13. Ad Hoc
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    Ad Hoc Naval Architect

    Do you have it in writing from the supplier what the grade of steel used is for their products? If so, is it on their own letterhead or a Class cert?
     
  14. redreuben
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    redreuben redreuben

    Ha ha, Chinese stainless, walk around your local marina and play spot the 316 (or not). Choy Lee's are infamous for it, couple of years old and rust streaming from every stanchion and fitting.

    You gets what you pays for.
    cheep cheep.
     

  15. Steve W
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    Steve W Senior Member

    Actually the very best SS fabrication i have ever seen is on a boat built in china that I did some work on a few years ago, presumably Chinese SS. The boat has not seen salt water yet so we shall see.

    Steve.
     
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