With Tiger® ceramic 4 in type 27 depressed center grinding wheels, there's no more compromise when grinding the toughest metals. Now you can maximize your time on the job with a superior combination of life and cut rate for maximum productivity. Self-sharpening and cool cutting, ceramic grains remove material effortlessly while a hard bond keeps working longer. The flat profile of the wheel in combination with depressed center allows for a wide range of grinding angles (0 to 45).ceramic grains utilize a crystalline structure that is designed with millions of fracture points that self-sharpen at a higher rate than other grains. The result is a higher material removal rate, faster cutting speeds, cooler grinding, and reduced friction at less pressure which reduces operator fatigue. For those that put a premium value on getting work done faster and optimizing grinding wheel usage on grinders, Tiger® ceramic delivers.