Summary for qq-p-35 type 2 Discussion
QQ-P-35 Type 2 vs MIL-S-5002 is discussed as a passivation-spec question for 303 CRES parts after a customer changed requirements. Dale Neff asks whether the two specifications differ and whether parts already processed to QQ-P-35 can be reprocessed to MIL-S-5002. Ray Kremer replies that MIL-S-5002 is freely available and that its passivation paragraph basically says to use QQ-P-35. He adds that QQ-P-35 is a canceled specification that now automatically refers aerospace users to AMS2700 and other industries to ASTM A967. According to Ray, there is essentially no difference between the replacement specs and QQ-P-35 for nitric acid passivation processes, though citric acid processes were added in the newer standards. The thread does not give a detailed reprocessing procedure, but it implies the specifications are functionally similar for nitric acid passivation.
Q. I work for a job shop and we don’t do any finishing ourselves but use vendors for the finishing process.
One of our customers was recently purchased by an large aerospace company and they changed the specification for passivization of 303 CRES from QQ-P-35 Type 2 to MIL-S-5002 Type II.
What are the differences between the specifications and can parts that have already been processed to the QQ-P-35 specification be reprocessed to the MIL-S-5002 specification?
Dale Neff
job shop – Los Angeles, California, USA
October 4, 2008
A. Dale,
Mil specs are freely available for download from https://assist.daps.dla.mil/quicksearch/
The paragraph in S-5002 about passivation basically says to use QQ-P-35.
I would also like to point out here that QQ-P-35 is a canceled spec, and itself automatically refers to
AMS2700 for aerospace and ASTM A967 for other industries. There is also essentially no difference between the replacement specs and QQ-P-35 as far as nitric acid processes are concerned, but allowance for citric acid processes have been added.
Ray Kremer
Stellar Solutions, Inc.
McHenry, Illinois
October 7, 2008
Thank you Ray Kremer for your prompt response and for the link to the documents. And thanks to finishing.com as well.
Dale Neff
– Los Angeles, California, USA
October 10, 2008