On Sun, 11 Sep 2005 09:01:43 +0000, xray wrote:


I did think about grinding on them to see what the sparks look like. I
think I have references in a book or two about differences in sparks.

When I first read about the spark test years ago I didn't give it
much credence for helping to identify the make-up of steels. Because
of my lack of experience I was unable to spot the subtle differences
in the spark patterns made by different types of steel. You can read
up on the spark test, and that's a help, but you really need to grind
on known types of steel and cast iron a bit to develop an "eye" for
the different spark patterns (or at least I did). At this point I can
touch an unknown type of ferrous metal to a grinder, observe the spark
pattern, and get a pretty good idea of what that steel's properties are.
I might not be able to give its chemical composition, but I can distinguish
between mild steel, high carbon, high speed steels, cast iron and cast steel
pretty easily.

Here's a web link that discusses steel identification, including the spark
test.

http://64.78.42.182/sweethaven/BldgC...Num=1&modNum=4

or

http://tinyurl.com/995c3