World's #1 finishing resource since 1989
No login needed: Chime right in
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 AMS-27005. 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
July 29, 2014
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 [link is to free spec at Defense Logistics Agency, dla.mil] specification of the US Military.
You won't go wrong technically using QQ-P-35 or its successor AMS2700 [affil. link to spec at Techstreet]. The only issue I see is getting customer agreement. Can you approach them and say "You meant QQ-P-35, right?"
metallurgist - E. Aurora, New York