PCB Suppliers,
     Continental Circuits (PHX) generally pin gauges holes to determine the
     actual size. Our SOP has been to use a pin
     .001 smaller than the bottom of the tolerance. That is, for a .043
     +/-.003 hole we would use a .039 pin. If this passes through
     with normal pressure, we say the hole is at least .040 and is in
     tolerance. I can't find this technique documented anywhere and have a
     customer who disagrees. They use the same size pin as the bottom of
     the tolerance.

     How do you measure holes? I could use some support for our method.

     Rich Olsen
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     Richard Olsen                Telephone (602)-232-9154
     Continental Circuits Corp.   Main      (602)-268-3461
     3502 East Roeser Road        Fax       (602)-268-0208
     Phoenix Arizona              Pager     (602)-310-6245
     85040-2905                   Internet  [log in to unmask]
     USA                    I make circuit boards,what do you do?
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