The Lawson Products Blue-Kote Soft Material Application Flap Disc is designed to grind aluminum and all non-ferrous metals at high speed with minimal clogging or loading, while keeping the work surface temperature low for quality finishing. The Type 27 abrasive disc can also be used with composite materials such as carbon fiber and plastics. The flap disc grinds and finishes simultaneously to save process time and eliminates the need for product changeover. The 4.5" diameter disc is available in 40 and 60 grit.