I have had CBN wheels for about 7 or 8 years now....let me tell you they are great. However....they are designed for HSS steel ONLY..... ie: lathe tools and basically nothing else. I have a genius nephew that used my shop in my absence, I have 4 bench grinders and only one with the CBN wheels.....he decided to use the "fancy wheels" on normal steel and stripped most of the diamond coating off them. He was "sure sorry", but broke...I changed the code to the door.....
In the words of Senator Kennedy of Louisiana...he is the reason there is instructions on a shampoo bottle.