When I am making a tool bit out of tungsten carbide, do I have to keep it
cool? Does heat change it's hardness, or does this just apply to tempered
steel?

Kori

"Kori" wrote in message
...
When I am making a tool bit out of tungsten carbide, do I have to keep it
cool? Does heat change it's hardness, or does this just apply to tempered
steel?

Considering brazed carbide exists, I don't think you have to worry about
that... Just don't cool it quickly (e.g. quenching) or you'll crack it.
I'd guess either going full-bore or slowly with a water-cooled stone.

Tim

--
In the immortal words of Ned Flanders: "No foot longs!"
Website @ http://webpages.charter.net/dawill/tmoranwms

What kind of heat are you talking?
Most Carbides will easily stand up to temperatures used to braze it to steel
shank holders.
However as with most things it won't do it any good if too much heat is
applied.
Gradual heating and cooling is ok. Quenching with water or compressed air may
lead to cracking of carbide.
If you are talking heating during grinder, you still want to avoid over
heating and cooling to quickly.

Kori wrote:

When I am making a tool bit out of tungsten carbide, do I have to keep it
cool? Does heat change it's hardness, or does this just apply to tempered
steel?

Kori

When I am making a tool bit out of tungsten carbide, do I have to keep it
cool? Does heat change it's hardness, or does this just apply to tempered
steel?

Carbide grinding should be done very wet or dry. If you have intermittent
cooling thermal shock will crack it.

I have had poor luck grinding brazed carbide toolbits with silicon
carbide grinding(green) wheels. They cut slow and edge is pretty rough.
Diamond wheels work very well.

chuck

"Kori" wrote in message
...
When I am making a tool bit out of tungsten carbide, do I have to keep it
cool? Does heat change it's hardness, or does this just apply to tempered
steel?

You don't have to keep it cool. It can glow red without suffering harm.
However, a brazed-on carbide tool bit will fall apart long before it gets
red, because the brazing material will melt.

Ed Huntress

In article , Ed Huntress wrote:

You don't have to keep it cool. It can glow red without suffering harm.
However, a brazed-on carbide tool bit will fall apart long before it gets
red, because the brazing material will melt.

You're okay up to dark cherry, normally, unless you're using a lot of
force. I sometimes have to 'unbraze' stuff, and you need a LOT of heat.
Mind you, I deal with large pieces, so that's going to colour my
perceptions.


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Mike Graham | Metalworker, rustic, part-time zealot.
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http://www.metalmangler.com| Caledon, Ontario, Canada