CBN or Cubic Boron Nitride grinding wheels are electroplated and nickel coated. Electroplating offers many advantages over other applications. It creates a more aggressive bond over other applications and will hold form longer. It also performs a higher stock removal rate and will last for years. They are designed for sharpening high speed steels only and should not be used for other applications. These wheels have a 1.5" face so they are easy to use and work well with the Wolverine Sharpening System. The 180-grit wheel puts almost a mirror finish on your edges and makes them "scary sharp."The 80-grit wheel whips your tools into the profile you want and you can even finish grind your tools with it as well as raise a burr for your scrapers. A unique feature of this wheel is the 1/4" radius on the left and right sides of the wheel. The radius makes it easy to grind small 1/4" hollowing bits and round scrapers. This eliminates the problem of having to rotate a tool by the handle (in the case of scrapers) and end up over-grinding the tip. This is a very handy feature, and you can hold the small bits and not burn your fingers. You won't find a better wheel at these incredible prices. Money back guarantee.