SLaifman@SoCal.rr.com wrote:
> Warning: The following material contains detailed technical
> discussions of materials testing, and is only provided for those
> wishing to pursue the subject. This is only a limited guide to some
> available resources, and is intended for technical review. This
> information is NOT provided to reflect on any strongly held beliefs on
> Ford production.
>
> A more likely production tool would be a Rockwell Hardness test,
>
> " The Rockwell hardness test method consists of indenting the test
> material with a diamond cone or hardened steel ball indenter. Small,
> portable test devices are available "
>
You can't use a Rockwell test on cast iron. The material is not
homogeneous and the Rockwell reading will be different if the penetrator
lands on graphite (dead soft), pearlite (hard) or ferrite (soft). The
big 10 mm ball hits a little of everything and gives a good
representation of the hardness.
Stanley P Rockwell was from Hartford and the heat treater bearing his
name is still here.
My sample of one crank that had a Brinnell does not qualify a statement
that all cranks had a Brinnell test, but I do think it is far more
likely that they ran a Brinnell test than a nodule count IF they were
100% inspected.
Bob
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