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Thread 596/64
Old passivation specification "3P-5"
July 9, 2014
Q. I have an old print (1962 was last change)
The print call out is "Passivate per 3P-5"
I cannot find any references to specification back that far. The part has not been made in the past 20 years and the certification for the last parts made are not available.
Was 3P-5 a proprietary specification in the 1960's or was it a common call out like AMS2700. I would like to be able to justify the change to the modern specification but I need to know what the original 3P-5 specification was.
product engineer - Akron, Ohio USA
publicly reply to Dan walker
A. Hello Dan!
If your part is stainless steel, I'd bet that's a typo -- we find such things far too often on our old, legacy drawings. A VERY common passivation specification at the time was the QQ-P-35C
[from DLA]
specification of the US Military.
You won't go wrong technically using QQ-P-35 or its successor AMS2700. The only issue I see is getting customer agreement. Can you approach them and say "You meant QQ-P-35, right?"
Good luck!

Lee Gearhart
metallurgist - E. Aurora, New York
July 29, 2014
publicly reply to Lee Gearhart
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