Optimize your right-angle grinding performance with Norton RazorStar Fiber discs, featuring engineered shaped ceramic grain technology for the best cutting performance in the industry. Designed for medium to high pressure metal removal in the toughest grinding applications, Norton RazorStar discs feature 100% engineered shaped grain which cuts through metal with unbeatable performance. Norton RazorStar F990S is setting a new standard in grinding productivity, speed and life. Speed-Change arbor mount allows fast, efficient disc changes without tools. HOW IS NORTON RAZORSTAR UNIQUE? Norton RazorStar discs with engineered shaped ceramic grain are a breakthrough technology specifically designed to deliver unbeatable grinding performance versus all other ceramic discs on the market today The unique combination of razor-sharp grains with a supersized grinding aid helps to significantly reduce heat generation for cooler cuts and longer life on all materials A single disc design has been optimized for superior performance on all materials including carbon steel, aluminum, stainless steel and hard-to-grind metals The engineered shaped grain in Norton RazorStar discs features a consistent shape from grain to grain along with razor-sharp cutting points. The unique patented geometry and tough micro-structure enable the grain to stay sharp, as new cutting points are exposed when the grain fractures. RazorStar discs also features a very high concentration of grains oriented in an upright position, so they are ready to cut and perform at their sharpest.