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Passivation - AMS 2700C vs ASTM A967 [California] 

October 21, 2009

Can you please tell me the differences between the passivation processes AMS2700C vs ASTM A967. I have a note requirement for the ASTM A967, Type 6 or 7 requirement on some parts and the parts were passivated to the AMS2700C, Method 1, Type 6 requirement.

Ted Nance
customer - San Diego, CA

The two standards are essentially equivalent. Both contain a carryover of QQ-P-35C with the addition of the more recently developed citric acid based process. The AMS standard is used by the aerospace industry while the ASTM standard is used by generally everyone else.

QQ-P-35B contained six nitric acid bath Types. The C revision removed four of those and added two, leaving as options, Types II, VI, VII, and VIII. A967 renumbers those to 1 through 4 (there is no such thing as A967 Type 6 or 7) while 2700 restores the missing four for a total of eight Types.

Ray Kremer Stellar Solutions, Inc. McHenry, Illinois