No registration, no passwords; no pop-up ads -- just aloha, fun, & authoritative answers.
As an eBay Partner & Amazon Affiliate we receive compensation for qualifying purchases.
Home /
T.O.C.
FAQs
 
Good
Books
Ref.
Libr.
Advertise
Here
Help
Wanted
Current
Q&A's
Search 🔍
the Site
pub  Where the world gathers for
plating, anodizing, & finishing Q&As since 1989





-----

Test for Type 316 vs. 304 Stainless Steel

adv.    koslow 316 stainless steel test kit


Q. I have about £1000 worth of perforated stainless steel sheets. The problem is that they are a mix of 304 and 316. There is a test that I know of. A chemical is applied to 316. It tests for the 'molyb-da-mum' (that's roughly how it's pronounced but I'm sure that it's not it's most accurate spelling) content in the 316. The chemical is green and turns brown when it reacts with the M word in the 316. As 304 does not contain any, the chemical stays green. My problem is I cannot remember the name of the chemical. Please help.

Ziya Ahmad
perforators - West Midlands, England
2000


ASTM STP550
ASTM_STP550_cover

A. According to ASTM STP 550, possibly available from the ASTM, the test for molybdenum in 300 series stainless is to

a) Place equal drops of concentrated hydrochloric acid and concentrated nitric acid on the metal surface. Allow 3 to 4 minutes for reaction and transfer 2 drops to a spot plate.

b) Add 2 drops of 10% potassium thiocyanate [adv: item on eBay or Amazon] .

c) Add 25% sodium thiosulphate [on eBay or Amazon affil links] drop-wise stirring until the red color begins to disappear. A violet color will appear if molybdenum is present.

However, I think your best course of action is to get a chemical spot test kit from Koslow Scientific Testing Instruments [a finishing.com supporting advertiser] or Systems Scientific Labs or some other company that makes them. A quick web search under "chemical spot test" should show manufacturers if they foolishly aren't already listed on finishing.com, and I know the two mentioned above offer small kits just for 304 vs. 316 resolution. Good luck!

lee gearhart
Lee Gearhart
metallurgist - E. Aurora, New York

Ed. note: Aww, shucks, you're just trying to embarrass us :-), but thanks! - finishing.com


A. Ziya,
Surely you can get the name of the 'green' chemical for identifying molybdenum somewhere in a local city. Try first a major supplier of chemicals and ask to speak to the lab technician first of all!

Failing that, contact a major supplier of stainless. OK? There's Henry Wiggin, too. Highly competent Company but specializing in the ultra high Ni.Mo alloys.

Mind you, had you a 'magnetometer' I'd guess that 3l6 would show a lower reading than 304. But that's pretty esoteric. Stainless does, yes, DOES contain some magnetism albeit of a low order.

Cheers !

freeman newton portrait
Freeman Newton [deceased]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).

2000



Q. How can I check difference in between 304-316 and 202? Please advise.

Harvinder [last name deleted for privacy by Editor]
-Delhi, India
2001


A. Hi, Harvinder.

If you have the money, a alloy sorter / scrap sorter [on eBay or Amazon affil link] hand-held XRF machine will instantly tell you exactly what each piece of unknown metal is -- but you're talking about $30-45,000 or so.

Regards,

Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey


A. Hello I have the answer for you I think over here it's named CELMO MOLYBDENUM REAGENT We are testing lots of 4301 and 4401 materials and have bought a small electrical tester MOLYTESTER. Look for Corrocean. I Hope you can use this information. Good Luck !

Johan Faber
steel trader - Almere (Holland)
2003




Need our Molytester calibrated

RFQ: We use in our company the Molytester for analyzing AISI 316. Our customers demands that this equipment must be calibrated by an independent institution. Does someone know where I can calibrate this equipment ?

Thanks !

Edwin Schieveld
test-research equipment - Dongen , Noord-Brabant, Netherlands
2003

Ed. note: Sorry, this RFQ is outdated so private contact is no longer available, but public technical replies are still welcome! No public brand/source suggestions please ( huh? why?)





"Rapid Spot Testing"
by Andrew Holmes

on Amazon

(affil links)

Q. We have a few SS316 materials fabricated and machined. There is no scope for cutting a sample to check the chemical composition. Also we are not in a position to go for handheld tester to test these materials as they are simply not available at the place of material. Is there any other method by which I can check the material.

Thanks,

Sunil Khanna
pharmaceuticals - Indore, India
2005

Ed. note: Whether a chemical spot test should be considered a non-destructive test or an out-of-scope destructive test is something you and the other deciders will have to decide, Sunil. Good luck.

A. I know of a way to tell the difference tween 304 and 316. this method has been used in recycling for years. It's called "spark test". With an angle grinder [on eBay or Amazon affil link] , grind 304 and look at the sparks; they will fork out at the end of their flight. 316 will spark but each spark will stay intact till the end of its flight. Try it out, it's cheap and better for the environment.

Bill Rucinski
- Hatley Wisconsin
2006




Q. I am into the construction and interiors line and have a problem: how would we be able to check to see if a kitchen basket of stainless steel is made of 202 or 304 SS? (If possible, some way where even a lay-man could check for him / herself) There are just too many instances of customers being taken for a ride. Thanks!

Kiran Khambadkone
construction / interiors - Bangalore, Karnataka, India
2007


A. There are two basic issues that requires solution.
Separate 304 and 316 and secondly how to avoid mix up of costlier 300 series SS with 200 series.

To name a few as Lee pointed out companies like Koslow Scientific Testing Instruments [a finishing.com supporting advertiser] and Systems Scientific lab have been segregating 304 and 316 for a few decades now through their kits. However, to do a cost effective segregation of 200 series which might get mixed up with costlier 300 series of SS has been a bit of a challenge. Also, both series, 300 as well as 200 series are non-magnetic.

However, The Indian Stainless Steel Development Association mentions one of the company in India i.e. Met Associates, Navsari who has a portable, economical and Non-Destructive method kit developed for both the issues mentioned above.

Please contact ISSDA for more assistance. Hope my response helps.

Milind Nanotkar
- Singapore
September 19, 2010




Q. DEAR SIR
WE ARE LOOKING FOR THE CHEMICAL TO DETECT MOLYBDENUM IN STAINLESS STEEL . WE HAVE FOUND SOME COMPANY SELL TOTAL KIT BUT WE NEED ONLY THE CHEMICAL. IS IT CALLED ELECTROLYTE?
WE WOULD BE GRATEFUL IF ANYONE ADVICE WHAT IS THE EXACT COMMERCIAL NAME OF THAT CHEMICAL TO FIND.
IT WOULD BE BETTER IF WE GET IN India.

MOSTAFIZ [last name deleted for privacy by Editor]
BUYER - CHITTAGONG, BANGLADESH
2007


A. I believe that Lee Gearhart's initial response answers your question, Mostafiz. The spot test book he mentions, ASTM SP550, is available from ASTM. Good luck.

Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2007


A. 1. Clean the steel surface; use abrasive paper, and if necessary degrease and dry.
2. Use "Decapoli 304/316" solution shake well, then place one drop on the steel.
3. Place similar drops on standard 304 and 316 samples.
4. Darkening of the yellow drop in 2 to 4 minutes indicates significant Mo. Compare with indications on standard samples.
5. Wash or wipe samples clean.

DDD Tuck
- East St. Louis, Illinois
February 3, 2008


A. The reader is looking for Damac 635 (or possibly 625) reagent to tell the difference between 304 and 316.

With regards,

PETER KEMP
- SURREY ENGLAND
March 7, 2008


adv.
The Koslow Scientific Company has a spot test kit called 304 vs. 316 Kit is an easy method to sort 316 from 304 stainless steel that we have been using this kit for years.

Lauren Keane
Koslow Scientific Company
supporting advertiser
Englewood, New Jersey
koslow banner
September 18, 2009


A. Go to search word "electrolyte for detection of molybdenum"

Charanjeet Singh
- New Delhi, India
May 15, 2010

Ed. note: Unfortunately, that search won't lead you to the generic chemical names you seek, Mostaviz -- it is a "cherry-picked search term" to lead you to one particular proprietary product :-(
But I think Lee Gearhart has answered your question already.

A. Hi Ziya,

Yaa, your doubt is correct. The element is "Molybdenum". And this is the difference between Gr 304 and 316 materials. Use "Elite folw findr" to identify the grade. The test is very simple. Clean the metal surface with emery paper and tissues and apply one drop of chemical on it. If it is Gr - 316 the colour of the liquid will turns to Brown within 3 minutes. And if it is Gr - 304 the colour will remains same as yellow.

Anilkumar Panicker
- UAE
October 12, 2011


TRILOK CAN BE USED TO FIND THE SS GRADE.

SARAVANAN PONNUSAMY
- SALEM/TAMILNadu, India
March 8, 2012


Q. Aslam o alaikum
Ziya, if you find the required chemical then kindly tell me also.

Muhammad Yousuf
- Lahore, Pakistan
March 30, 2012


A. Hi Muhammad.

Ziya last posted here a decade ago, so probably doesn't monitor this thread. But the question appears to have been answered by Lee Gearhart and others. If I'm misunderstanding, or if they haven't answered the question you have in mind, please re-state it.

adv.
Please remember that this free forum can only exist with support from advertisers like Koslow; suppliers who won't support the site with their advertising dollars but try to steer you towards themselves and away from our supporting advertisers are working towards making sites like this non-feasible :-)


Thanks!

Regards,

Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
April 3, 2012


A. Molybdenum electrolyte is the chemical, I use to check it.

Khalid Mehmood
- Punjab, Pakistan
March 7, 2017


Q. Would you please tell me the chemical composition of that electrolyte?

WALIULLAH WALI
- Dhaka, Bangladesh
January 9, 2024

Ed. note: Sorry, Khalid Mehmood hasn't posted here for years. If you wish a proprietary chemical kit please contact Koslow Scientific Testing Instruments [a finishing.com supporting advertiser]. If you want the generic chemistry, please see Lee Gearhart's posting and/or ASTM STP550.



Q. I just want to ask that what chemical reaction takes place while testing the S.S 316 using moly chemical testing kit?

Susheel khantwal
- india, dehradun
August 5, 2014


The chemical reaction is the development of a bright pink color.

Wolf Koslow
Koslow Scientific Company
supporting advertiser
Englewood, New Jersey
koslow banner
October 24, 2017


A. Hi. Inox 316 has a reddish tint whereas inox 304 has a whitish tint.

Rez Din
- Phoenix, MRU
October 24, 2017




Q. Can you please elaborate the procedure to detect the MOC-grade of a SS material using molybdenum kit.
This requirement is based on equipment qualification studies to be carried out at pharmaceutical manufacturing units.

Vishal Mishra
Alembic Pharmaceuticals Limited - Vadodara, Gujarat, India
August 20, 2018


A. Hi Vishal. Lee Gearhart points us to the ASTM procedure for the test above, and vendors like Koslow Scientific Testing Instruments [a finishing.com supporting advertiser] instruct you in the suggested procedures for their kits. Good luck.




Regards,

pic of Ted Mooney
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
August 2018




(No "dead threads" here! If this page isn't currently on the Hotline your Q, A, or Comment will restore it)

Q, A, or Comment on THIS thread -or- Start a NEW Thread

Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories:

 
Jobshops
Capital
Equipment
Chemicals &
Consumables
Consult'g, Train'g
& Software


About/Contact  -  Privacy Policy  -  ©1995-2024 finishing.com, Pine Beach, New Jersey, USA  -  about "affil links"