On Wed, 24 Sep 2008 16:50:27 -0500, "Robert Swinney"
wrote:

snip
Drop a 1" diameter ball bearing from a height of 10". It should rebound back up to 9" if the anvil
surface is properly heat-treated. I'm not sure I believe this. Can someone confirm?

I've heard of building your own hardness tester using this
method.

You need some known items of hardness for calibration
though. Find some glass tubing maybe 10-20 inches long that
you can make marks on and your steel ball will easily slip
into. Using a known surface drop the ball (from the same
height) and note (mark) how high it bounces up. Repeat
several times and take the average. Repeat process on
another known item. Test your unknown item and note how high
the ball bounces.

--
Leon Fisk
Grand Rapids MI/Zone 5b
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