Harold & Susan Vordos wrote:

uh oh. I have some diamond wheels that are solid steel with a
diamond coating that seems to be embedded directly into the steel.

I can't comment on your wheels but I have some diamond shapening
"stones". I've had these for many years so the manufacturing technology
may have changed but the manufacturer of mine included a little pamphlet
on how they were made.

They started with a flat steel plate. This was placed horizontally in a
nickel plating bath and the plating started. During the plating
operation, diamond particles were drizzled through the solution onto the
plate. The details of just how this was done in a controlled fashion
were not revealed. The result was a steel plate coated with diamonds
embedded in a nickel matrix.

These are very fast cutting. For _serious_ sharpening of knives or HSS
tools, I start with the diamond hones then go on to a Wa****a, Soft
Arkansas, Hard Arkansas and Black Hard Arkansas. I'm very glad I got my
Arkansas stones many years ago as I understand the material is becoming
very scarce and the stone quality isn't what it used to be.

Interesting. The use of diamond on steel is not generally acceptable.
Diamond in contact with hot steel does the same thing that silicon carbide
does, it dissolves into the steel. When that happens the diamond has very
short life, gets dull quite fast.

I believe the key word here is "hot". I've read that a diamond wheel
should not be allowed to throw sparks when grinding steel. If it does,
you are being too agressive. I have a diamond wheel one on my Foredom
that has been in use for several years for fine stuff.
anyway. The lone exception is if the wheel runs so slow that it doesn't
generate red heat. Low speed diamond lapping wheels are used for steel
with success.

Wot he said! :-)

Ted