Black Silicon Carbide For Shaping Carbide Tool Bits?

I have been satisfied with using green wheels to chew away carbide and steel. They kind of work, and keep the steel away from the diamonds. Then, you can use an inexpensive diamond wheel on a rotary tool to just give the edge a touch. Or those diamond hones or sticks also work. The main thing is to keep the steel part of the brazed tools off the higher speed diamond wheels. It seems to work for me. When the edge is in the right shape from the green wheel, a few rubs on the stick really helps the edge cut a lot smoother.
 
Interesting. Maybe it is just me that has trouble using green wheels on carbide. I never got any carbide sharp using one, maybe it was the wrong type or I was using it wrong. All I got was a lot of wheel dust, a hot tool, and had to hone the hell out of it with a diamond hone to get it sharp afterwards. Regardless, now I have a carbide grinder with a diamond wheel and am too hopelessly spoiled to try the green wheels again...
 
Both types of wheels have their place; crash a carbide tool, the diamond wheel would take way too much time to whittle away the damage and cause undue wear to it; the green grit wheels, if fine enough can both rough off damage and finish to a adequate cutting edge for most purposes' If the tool is damaged much, we would grind the tool shank under the carbide with an ordinary aluminum oxide wheel, then work on the carbide. The green grit face wheel we used was fairly fine, and coolant was used in volume.
 
Both types of wheels have their place; crash a carbide tool, the diamond wheel would take way too much time to whittle away the damage and cause undue wear to it; the green grit wheels, if fine enough can both rough off damage and finish to a adequate cutting edge for most purposes' If the tool is damaged much, we would grind the tool shank under the carbide with an ordinary aluminum oxide wheel, then work on the carbide. The green grit face wheel we used was fairly fine, and coolant was used in volume.
Thanks, John. I was using a 6" 80 grit Crystolon tool room wheel, tool steel shank undercut with aluminum oxide. but the carbide never got sharp enough to be useful. Perhaps it was the lack of any coolant.
 
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Most all the lathe guys used the black wheel on a bench grinder for sharpening brazed on tools, it had no coolant, and the sharpening job was good enough for the work done; it is true that the better the tool edge, the better the finish, but we had plenty of files and emery cloth too, and a good bit of work was ground as well. We used insert tooling as well, but it was all negative rake and used mostly for roughing, both for lathe work and milling; note that this was back in the 1960s when positive rake tools were not much used, and where I worked, there was a prejudice against them "because they had only half the cutting edges than negative rake tools". The fact that positive rake tools are more productive in terms of metal removal did not enter into the equation. The clo9sest we got to positive rake was by grinding a chip breaker into the brazed tools with the black grinding wheels.
 
If You want to see a wheel disapear quickly, just grind steel on a green wheel. It must be seen to be believed.
 
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