Sound technical content, curated with aloha by
Ted Mooney, P.E. RET
Pine Beach, NJ
The authoritative public forum
for Metal Finishing since 1989
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Testing for 304 vs. 316 Stainless Steel?
Q. Hi there, I once saw an engineer personnel use a small machine to determine the Moly in it to evaluate if its a 304 or 316 material. I was wondering if anyone know the name of it and where could I find one in Canada. Thanks for you help. :)
Bob Lum2006
A. Letters 6060 and 33549 don't name a specific machine, but do describe chemical tests and a simple spark test, Bob.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
A. In previous employment we used a yellow liquid (the bottle was covered in french writing). By removing the surface oxide using emery cloth and pouring a small amount of the liquid on this area it turns brown if there is molybdenum present. If there is no molybdenum then it remains yellow. So if it turns brown it is 316 if it stays yellow it's 304.
Neil Tokell2006
A. I would suggest portable XRF.
Terry Tomt2006
2007
Q. I am Abbas from Malaysia
I want to know how to differentiate SS304 and SS316
I saw some people test the both by liquid and a battery
A drop of liquid in the stainless steel surface and keep the one side of the battery in the liquid and other on the Stainless steel itself:
if the liquid drop turns red then it is SS316 otherwise SS304.
If anyone knows about this please let me know the following
1) What is that liquid
2) Composition of that liquid
3) How to get that liquid
4) what is the name of the test
I will be more thankful if anyone let me know about this.
Q. I want to know what is the easiest way to find out difference between 304 grade and 316 grade? Like any simple test, because both look alike, and workers are not able to figure out which is 304 and 316?
Peter JacobFebruary 23, 2008
Q. My name is Alex from Nigeria, please what is the easiest way to test for a 304 and a 316 respectively, please I need your help because it is bringing a lot of problems, people are confused on which is 304 and 316... please I will really appreciate if my request is granted please.
Alex FaithJuly 11, 2011
A. Hi, cousin Alex.
Hi Alex. We'd like to help you, but we don't understand how when we've already printed several in-depth discussions on the topic, and you simply ask again without offering any clarification of what you are not understanding, nor any special circumstances. But we'll try: A alloy sorter / scrap sorter ⇦ this on eBay or Amazon [affil links] hand-held x-ray fluorescence machine is the fastest and easiest way, and it is non-destructive. But they cost $30 thousand U.S. and up. Will that be a satisfactory answer or do you need a cheaper, but slower, slightly destructive, and somewhat less certain chemical test?
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
July 12, 2011
Q. I am looking for a simple practical, "back yard-type" method of determining the difference between 304 and 316 stainless steels. I do a fair amount of "hobbyist" work with Stainless steels and most of my metal comes from scrap yards. I need to be able to determine the difference between the two grades. You had a post in your column a few years ago about using the "spark" method (which I unfortunately did not download - dumb me !) This described the "feathering" of grindstone generated sparks at the end of their travel before cooling and disappearing from sight. The spark from either the 304 or the 316 stainless split-up (feathered) at the end of its travel. My question is WHICH TYPE ??? "feathers" many thanks in anticipation. Regards, Collin Berrington
"STAINLESS RULES"
July 30, 2013
A. Hi Collin. The posting you are looking for is Bill R from Hatley, Wisconsin's response on letter 6060.
In letter 44899, Robert G from Monterrey, Mexico complains that spark tests do not work for him, whereas Don O from Montreal describes another difference in the spark from 316. Good luck.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
July 2013
A. The simple way is to buy a certified sample of each in your most common shape and size. Try both on the grinder and see what differences there are. Everyone sees things a bit differently.
James WattsNavarre, Florida
July 31, 2013
July 30, 2013
Hi Ted,
Many thanks for your prompt reply. The spark test as posted , "works like a bomb" ! I can now easily differentiate between 304 and 316. As one commenter stressed, "we all see things differently", however with a little practice (of which I get Lots), it becomes easier as one goes along.
Your advice, greatly appreciated.
Kind regards,
adv.
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