I have designs with gold plated contact areas on microwave stripline circuits.  The contact area is used to make a pressure connection between the circuit and
an RF connector.  The connection is made by compressible gold mesh (super
miniature brillo pad) placed in the space between the circuit contact area and 
the center pin of the RF connector.

The drawing currently specifies gold plating per Mil-G-45204, Type II, Grade C,
Class 1.  Our supplier has requested that they be allowed to use Grade A
(softer) gold instead.  IPC-D-275 does not recommend Grade A for contact areas
but I think this is based on a wiping action across the surface when the 
connection is made or broken (eg. connector fingers) and the soft gold would not
provide adequate wear resistance.  Our design has the contact area under 
continous compression.  

Anyone have any experience which would indicate the Grade A gold would be a poorchoice in this application?

Thanks for your help.

Jeff Rowe
Lockheed Martin
Syracuse, NY
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