Thread: Brazed Tungsten Carbide lathe tools

I have a number of Brazed Tungsten Carbide lathe tools that require some dressing to make them serviceable again. When I was in the trade (machinist), many years ago now, we always used Silicone carbide grinding wheels.
I've been contemplating for sometime purchasing as second grinder for use as a dedicated sharpening machine.
But after seeing what is available in the way in Tungsten insert tools and the relativity low prices, I'm beginning to wonder if I should just ditch my old brazed tip tools and replace with Insert tools ????????

Originally Posted by Oldhack

I have a number of Brazed Tungsten Carbide lathe tools that require some dressing to make them serviceable again. When I was in the trade (machinist), many years ago now, we always used Silicone carbide grinding wheels.
I've been contemplating for sometime purchasing as second grinder for use as a dedicated sharpening machine.
But after seeing what is available in the way in Tungsten insert tools and the relativity low prices, I'm beginning to wonder if I should just ditch my old brazed tip tools and replace with Insert tools ????????

If you want to resurrect these without paying a bomb your could try a diamond lapping wheel like this 6" one I have on the side of my CBN wheel
The diamond wheel cost about ~$10 from Hong Kong and they come in a range of sizes and grits.
As well as TC bits I use mine to sharpen TIG tips.

TP2.jpg

Forgive my ignorance BobL, but what is a CBN wheel ?????

Originally Posted by Oldhack

Forgive my ignorance BobL, but what is a CBN wheel ?????

Cubic Boron Nitride - it's for HSS.

Originally Posted by BobL

Cubic Boron Nitride - it's for HSS.

But don't let that stop you from using it to grind Carbide tooling.

Originally Posted by BobL

Cubic Boron Nitride - it's for HSS.

interesting, I've always just used Aluminium Oxide for HSS

Originally Posted by Oldhack

interesting, I've always just used Aluminium Oxide for HSS

They are quite expensive but don't required dressing and don't wear away like standard abrasive wheels so don't change size. With the base wheel being made of steel heat is readily conducted away from the wheel so grinding is significantly cooler than with regular abrasives.

There was some discussion recently about how quickly they wear (ie wearing faster than expected) but further discussions on the woody forum reveal that when new they are extra aggressive, so once the highs points are worn off the boron nitride crystals, users think the wheel has worn out but the wheel will keep abrading material for a long time after that. Mine is about 5 years and while it is definitely not as aggressive as when it was new it still works fine.

Add to Bob's list of advantages that CBN wheels don't fling abrasive dust all over the place.

Originally Posted by BobL

They are quite expensive but don't required dressing and don't wear away like standard abrasive wheels so don't change size. With the base wheel being made of steel heat is readily conducted away from the wheel so grinding is significantly cooler than with regular abrasives.

There was some discussion recently about how quickly they wear (ie wearing faster than expected) but further discussions on the woody forum reveal that when new they are extra aggressive, so once the highs points are worn off the boron nitride crystals, users think the wheel has worn out but the wheel will keep abrading material for a long time after that. Mine is about 5 years and while it is definitely not as aggressive as when it was new it still works fine.

Thanks BobL, I'll have to research them further.

Just getting back to the diamond lapping disk, I thinking I could machine a aluminium face plate, to suit my bench grinder, and mount it to that. ?

Originally Posted by Oldhack

Thanks BobL, I'll have to research them further.
Just getting back to the diamond lapping disk, I thinking I could machine a aluminium face plate, to suit my bench grinder, and mount it to that. ?

Sure - Mine is 150mm in diameter and has a 100mm diameter x 10mm thick steel disk behind it that acts as a big washer for the CBN wheel.

Thanks BobL, I can definitely feel a project coming on, LOL.

Just as side note, what grit do you use ??

Originally Posted by BaronJ

But don't let that stop you from using it to grind Carbide tooling.

@ ~$200 a wheel. Probably not.

just came across this diamond wheel on Ebay, apart from the grit size would it be a batter option than the disks as mentioned above

https://www.ebay.com.au/i/262394758208?ul_noapp=true