Durable Sanding ClothOur 3M™ Cloth Roll 384F is best suited for metal sanding and finishing thanks to its durability and fast cutting abrasive material. Made with a flexible and waterproof polyester backing, this cloth roll provides smooth operation and durability which can conform to the shape of contoured parts for consistent finishing. The abrasive side features a closed coat of aluminum oxide grains to provide a fast cut and a fine finish.Aluminum Oxide AbrasiveAluminum oxide is a popular choice among industrial professionals because of its fast cut-rate and long life. This mineral makes a tough, durable abrasive that self-fractures to expose fresh cutting edges, whereas traditional natural abrasives dull more quickly. Due to its fast cut-rate, hardness, and strength, it is widely used for sanding and finishing applications. Aluminum oxide is suitable for use on a wide variety of materials in metal and woodworking.Waterproof and Heat Resistant3M™ Cloth Roll 384F also uses a resin bonding which is specially designed to resist thermal and chemical deterioration, which can occur during sanding. This bond is very tough and allows for fast sanding and a high cut rate. This makes it excellent for precision work on both hard and soft surfaces. The waterproof polyester backing material enables the belt in a woodworking application to rinse areas of the workpiece and the roll during use to prevent dust and debris from clogging the points of the abrasive, while producing a faster cut and extending the abrasive's life.