Validate stainless steel

Dear all,

I’m writing validation documents for a tablet press. logically I should have a stainless steel certificate of the tablet press. But because the machine is very old no certificate was available. My question is, how should I continue? If i don’t have the document, I can’t prove that the machine is from stainless steel and thus would the validation documents not be complete.

I’m looking forward to the replies!

You can done it by testing
Acid testing is one test that will separate 304 and 316 grades of stainless steel.:-
Sulphuric acid strongly attacks 304 grade, producing green crystals and a dark surface, but its attack on 316 grade is slow and produces a brown surface
Hydrochloric acid attacks 304 grade very rapidly and produces gas, but attacks 316 grade only very slowly.


Moly Test
A simple test is molybdenum content only because SS316 have 2to 3 % Mo where as SS304 does not have molybdenum.

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That’s great Mr. Rakibul Hassan the acid test is the most suitable

@RAKIBULHASSAN thank you very much for your response. is there any other test without damaging the surface of the equipment?

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Are there any markings visible on the product contact parts?

No nothing at all. I have fully checked it

what is the procedure for performing moly test?

Moly Kit: Consist of Molybdenum test solution and electrode.
Pour drop of Molybdenum soln in product contact surface
Place carbon electrode in electrolyte soln
put other electrode in specimen surface
if dark red colour persist for 60 sec then its SS 316, if less than 30 its 304
if black-202 grade