On Sat, 30 Apr 2005 21:28:26 GMT, "Boris Beizer"
wrote:

1. On a hunch, or perhaps it was something someone said earlier, I checked
those stellite bits and found that they are not magnetic. So back to the
bit bin and pulled out all the non-magnetic bits. It included:

a. All the stellite bits and blanks.
b. Some called "Tantung G."
c. Some called 525.

Are these latter two also Stellite? If it's not magnetic, is it
Stellite?

Tantung is a modern alloy similar in performance to Stellite. I
believe it's made up of similar elements as well. It's supposed to be
better than Stellite but I've not managed to use them both in the same
setting enough to prove that. I do know that Tantung didn't hold up to
a sever interrupted cut in stainless job that I did. But the fact is I
had problems with cheap cobalt bits holding up in that same situation
and had to go with good quality HSS bits.

The Tantung did hold up better than Cobalt bits in another part of
the same stainless job but I never felt it held up any better than the
old Stellite bit we tried on that job first. The reason we went with
the Tantung was because we couldn't buy Stellite.

I've not heard of 525 but it sounds more like a carbide designation
to me.

2. I noticed that some of my non-magnetic bits had an etched notice
"cutting surface." I've never seen that before. The tool blank doesn't
seem to be a composite. What is this?

I've seen a very few bits that are composite but are ground in such
a way that it's hard to tell.

3. I noticed that all the ground stellite bits had the cutting surface
opposite the etched "stellite" label. Is there a preferred cutting surface
for stellite? Or was it just to be able to keep track of what kind of bit
is what.


I'm betting that it was just the first persons to grind the bits
habit to put the label there. Most I've seen have been ground with the
label on the side.

Wayne Cook
Shamrock, TX
http://members.dslextreme.com/users/waynecook