# How do I tell stainless steel from carbon steel?



## austexdude (Nov 4, 2008)

Is there a sure fire way to tell?


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## austexdude (Nov 5, 2008)

To elaborate...I know how to test it over a period of a few hours, but I was looking for something a little quicker on the fly...


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## Harold_V (Nov 5, 2008)

One way is to heat the material. If it readily oxidizes and turns bluish black, with scaling, it's carbon steel. 

Stainless will generally tolerate greater heat without scaling, and turns a brownish color in the process. Of course, the alloy makes a big difference. The 300 series of stainless is non-magnetic, which is a good test for much of the stainless you'll encounter, but not all. In a work-hardened condition, even the 300 series can be mildly magnetic. 

Color is also an indicator, again, depending on the alloy. The 300 series all have a yellow cast, very unlike carbon steel. 

300 series is not affected by nitric acid. It is used for nitric storage and distribution. 

Harold


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## Anonymous (Nov 5, 2008)

the lack of stains would be a good indicator of stainless steel. :lol: Na, just kidding. To me stainless always looks different, whiter to me.


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## koebeef (Feb 26, 2009)

Do you have a grinder?
If yes gring the material. If it sparks orange and the sparks go far ( I am talking like 2-3 feet and make star shapes at the ends they then you have carbon steel. If it sparks a slighter reddish hue and stays short in distance then you have a stainless alloy. The redder and shorter the spark the higher the MOLY content in the material and the higher the value (i.e. a 316L as opposed to a 304L SS Alloy)

Hope this helps

Or you can buy a Niton tester for 35 Grand lol


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