3M Cloth belt 577F features alumina zirconia abrasive grain for increased cutting efficiency over aluminum oxide belts and is backed with a heavy, water-resistant polyester backing that stands up to high-pressure applications and edge work. The durable backing ensures long life and supports both wet and dry operations. - Alumina zirconia mineral with a grinding aid provides more cutting power than aluminum oxide across all metal types. Heavyweight cloth backing provides durability for high production environments.