Hardness and abrasion capability

Never used a Worksharp myself, but i think the principle would work the same.
I have been using various diamond compounds on Paper Wheels as well as coarse diamond powders on Rubber Wheels for a few years now with good results.
 
I have diamond belts for my Bubba'd HF 1x30". I also run it very slow compared to the stock motor.

They work pretty well, but it's almost faster to manually use DMTs. They are fantastic for cosmetic work though.
 
Sorry for bumping this old, but awesome thread. I was hoping to get some input on boron carbide versus cubic boron nitride (CBN) against vanadium.

CBN is rated almost twice as hard as vanadium and boron carbide is only slightly more hard than vanadium, but since it’s still harder, would boron carbide cut vanadium as effectively as CBN?
 
MRpink said:
Sorry for bumping this old, but awesome thread. I was hoping to get some input on boron carbide versus cubic boron nitride (CBN) against vanadium.

CBN is rated almost twice as hard as vanadium and boron carbide is only slightly more hard than vanadium, but since it’s still harder, would boron carbide cut vanadium as effectively as CBN?
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Boron carbide would not cut vanadium carbides so rapidly as CBN would. But it would still cut it, and given the small size of vanadium carbides I wouldn't be particularly worried about the ability of the boron carbide to cut it.
 
I am not aware of boron carbide stones being offered often and with different grits?
Gritomatic seems to have a few, but they are as expensive as diamond stones.
Just curious why to choose boron carbide stones?
 
miso2 said:
I am not aware of boron carbide stones being offered often and with different grits?
Gritomatic seems to have a few, but they are as expensive as diamond stones.
Just curious why to choose boron carbide stones?
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Boron carbide isn't often used, but its advantage is it's about half the cost of CBN and so bonded abrasives, while still expensive, aren't outrageously so. It's usually used to make grinding wheel dressing sticks since it's harder than silicon carbide.
 
FortyTwoBlades - thanks, I’ll try CBN.

miso2 - I’m looking into boron carbide/CBN emulsion to apply onto felt belts.
 
MRpink said:
FortyTwoBlades - thanks, I’ll try CBN.

miso2 - I’m looking into boron carbide/CBN emulsion to apply onto felt belts.
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It's worth noting that CBN and diamond have almost identical grain shapes and that diamond is a good deal harder, while costing about the same. The main reason anyone would choose to use CBN over diamond is for high-speed dry grinding of ferrous metals because carbon can migrate out of diamond abrasives and into the steel when the surface temp gets sufficiently hot, which is not a great thing to have happen. This doesn't occur in manual sharpening, however. In the knife world, CBN is mostly used for marketing reasons rather than functional ones.
 
Then my +/- 1400-1700 r.p.m. slow-speed grinder must be just slow enough to keep the diamond grit (and the edges) from overheating, as i've been using the same +/- 170 grit diamond & wax coated Rubber Wheel since August 2016 to this day.
The resulting scratch pattern is slowly becoming finer over time, but the diamond particles still abrade (high carbide volume) steel quite well.
 
Slow speed is the key word. The higher the speed, the worse/quicker the wear. Keeping the heat down is a function of both lower speed and liquid cooling - liquid cooling is pretty good as long as it's of sufficient volume and directed in just the right place. In the machine shop we use higher speed water cooled diamond wheel grinders for tungsten carbide tool sharpening. It is immediately apparent when someone has been using one for steel.

For something that just has some diamond grit pasted onto a wheel it's not as big a deal as the wheel just slows down and cuts at an effectively finer grit. When you have a resin bond or metal bond diamond abrasive wheel it becomes a big problem very quickly as the wheel geometry gets destroyed rapidly. It's also less of a problem when just doing light finish grinding with light pressure on a paper wheel or diamond belt. Less heat is generated in the first place.

Steel can actually be machined with diamond if it's done at low enough speed. The problem is that it must be so low that it isn't productive at an efficient cost except in very special circumstances.
 
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