"Terry" wrote in message
oups.com...
How about some diamond coated (or similar) sand paper mounted to the
back of one of my turning tools. The magnet is only 2mm thick.

I don't know of any such sandpaper (it may be around, I've just not heard of
it), but how much material do you have to remove?


Not sure what grit would be best though. Maybe a 220 or 400? Then I
could flood that with water, and change it frequently. Just a thought.

Ed: What radius insert would you recommend for turning a ceramic
magnet that is 2mm thick. I am going from 12.5mm dia. down to 10mm
dia.

First, that kind of unusual-but-practical information is not something I
would know from experience. My way of finding out such things is to look it
up or to go directly to the experts and ask them. This is 'way outside of my
knowledge.

Second, if you have to remove 2.5 mm of hard material, I think the sandpaper
idea will become a career g, but you'd better get some other opinions.

Third, although I have no specific info, here are a couple of general ideas.
Sintered ceramics usually are ground, not single-point turned. When they
machine engineering ceramics in production it's usually done with green
(unsintered) ceramics, or with glassy ceramics that are made to be machined
(Macor, for example).

I don't know anything about the machining properties of magnet ceramics. In
general, again, you turn or mill friable materials with the smallest cutting
edge and the slightest feedrate you can -- a sharp tool, in other words.

But ceramics vary widely in their properties, and this is one you could only
learn from experience, unless you trip across someone else's account of how
it's done -- from experience.

Good luck. Probably it's doable, somehow. I just don't know where to send
you for information, beyond the makers of the material itself.

--
Ed Huntress