Which diamond cutter is best suited to sharpening carbide cutters and gravers?

[ChristheClockGuy]

Hi, I will need to sharpen occasionally some carbide gravers / cutters at some point. My research has led me down the route of using a diamond wheel followed by a fine diamond lap. However when I look online at diamond wheels they come either as a solid disk like a standard grinding wheel or as a cup with a diamond external ring.. Can someone explain my best route and what is the different uses of these wheels. Also are the Ezelap stones good, do they need water or oil and what grade(s) would be a good choice.

Chris

 

[Martin W]

Hi Chris
I use diamond cup wheels with a diamond external ring to sharpen brazed carbide tipped circular saw blades. These would work good for carbide scribers or cutters and end mills. They come in different grits and diameters. Mist coolant dramatically extends the life of the cup wheel . I use water soluble cutting oil on mine. One down side is that they are very expensive. Not familiar with EZELAP stones. According to their website no water or oil is necessary.
Cheers
Martin

 

[ChristheClockGuy]

Hi Chris
I use diamond cup wheels with a diamond external ring to sharpen brazed carbide tipped circular saw blades. These would work good for carbide scribers or cutters and end mills. They come in different grits and diameters. Mist coolant dramatically extends the life of the cup wheel . I use water soluble cutting oil on mine. One down side is that they are very expensive. Not familiar with EZELAP stones. According to their website no water or oil is necessary.
Cheers
Martin

Thanks Martin,
I am now minded to buy a set of 3 50mm diamond lap wheels that I can run off my Sherline lathe. Diamond wheels disintegrate apparently with heat so runny slow and with little pressure seems important to preserve the disk life. Also protecting the lathe table from debris. I am minded to make a clip on table for the angles i need which will also protect the table.
regards
Chris

 

[Bob Korves]

Somewhere around 250-300 rpm when using 5-6" diamond wheels works well for power lapping carbide cutters for hand held tools, roughing with 600 grit and finishing with 1200 and 3000 grits. Can be done by hand without power as well with careful techniques.

 

[ChristheClockGuy]

Somewhere around 250-300 rpm when using 5-6" diamond wheels works well for power lapping carbide cutters for hand held tools, roughing with 600 grit and finishing with 1200 and 3000 grits. Can be done by hand without power as well with careful techniques.

Thanks bob yes I may well get a couple of Lap blocks as well. The wheels will be very useful for making one off tungsten carbide tools from small rods.
Chris

 

[pontiac428]

I grind a lot of general purpose cutters with a cheap China cup wheel (ring type you describe). They are not supposed to be used for HSS, but they aren't CBN, they're industrial diamond, and they hold up well especially considering the price. They do great on carbide. I hone by hand on a 1000 diamond lap for HSS, and only sometimes lap carbide because it finishes smooth on the wheel. I own a lot of laps, and for most cutting tools the 1000 does right. If you do a lot of HSS, you should consider stones instead of diamond, but if you can only have one wheel the diamond serves well.

 

[ChristheClockGuy]

I grind a lot of general purpose cutters with a cheap China cup wheel (ring type you describe). They are not supposed to be used for HSS, but they aren't CBN, they're industrial diamond, and they hold up well especially considering the price. They do great on carbide. I hone by hand on a 1000 diamond lap for HSS, and only sometimes lap carbide because it finishes smooth on the wheel. I own a lot of laps, and for most cutting tools the 1000 does right. If you do a lot of HSS, you should consider stones instead of diamond, but if you can only have one wheel the diamond serves well.

Thank you that is really helpful
Chris