After my near catastrophic bench grinder incident I decided to try the CBN grinding wheels. I got my wheels from woodturnerswonders.com. I got the 80 grit and 350 grit 8" wheels based on their recommendation. The wheels are the 4 in 1 design with grit on part of the side and with 1/4" radius corners. The wheels are absolutely beautiful. At 1-1/4" wide they fit in the factory guards. I did have to make a 1/4" spacer to center the wheels in the guard. All I can say about them is WOW! These things are awesome on HSS. As a test, I ground this 3/8" tool in about three minutes free hand. Not my best work but I wanted to see how well the wheels worked. I think I wet the tool twice. The 80 grit removes material like nobody's business with very little heat. Amazing.