The ceramic alumina abrasive on these pads is sharp and dense enough to shape hard metals such as stainless steel, nickel, and iron without dulling quickly. They’re often used to sand inside pipes and tubes, or to sand at an angle when reaching into corners and slots. The abrasive material on these pads continuously fractures to produce new, sharp cutting edges. They sand faster and last longer than aluminum oxide but require more force to abrade properly. A shank adapter (sold separately) is required.