What is this wheel for?

[moonlight machine]

My surface grinder came with 2 extra wheels, marked Norton CBN wheel 560783 CB120-TBB-1/16 max rpm 6050 What are they for? Do they need coolant?

 

[RJT]

We use CBN for hardened tool steel only (58 RC or harder). I don't know what your numbers mean (I would call Norton), but they are expensive wheels and when used in the right application, they are exceptional.

 

[John in CA]

I threw a CBN wheel on a spindle one day to grind some carbide, mistakenly thinking it was a diamond wheel. Found out by accident it will actually do a passable job. Better than Silicon carbide, finish-wise, but not as good as diamond. However, I don't know whether carbide would damage the wheel if used for this purpose long-term, so I'd only try it again if I were really in a pinch.

 

[huntinguy]

http://www.grindwellnorton.co.in/BrochureWare/sa_diamond_CBN_46.htm

I think it means they are cubic boron nitrite at 120 grit 062 wide. Don't know about the TBB, unless it is wheel shape... but that is only a guess.

I don't have my book in front of me at the moment.

 

[salvor6]

I thought the 1/16 means the depth of CBN, just like on diamond wheels.

 

[huntinguy]

salvor6: me thinks you are correct. Too many things on my mind and darn few in it.

 

[cash]

You will want to use coolant. Oil based or semi-synthetic is the best but a full synthetic will do o.k. as well for light grinding.