The 3M™ Cartridge Roll 747D is ideal for metal finishing in small, hard-to-reach areas like corners or inside pipes. These cartridge rolls feature a blend of aluminum oxide and 3M ceramic grain on a strong cotton backing around a solid mandrel core. Available in both tapered and regular designs.The surface of the 3M Cartridge Roll 747D is covered with blended ceramic materials, which enhances the toughness and hardness of the grain. Perfect for stock removal, ceramic abrasives are engineered to fracture frequently for a super-fast cut and can handle intense heat and stress applications. The ceramic/aluminum oxide blend makes the 3M Cartridge Roll 747D an excellent choice for moderate stock removal and surface preparation. Abrasive grains are attached to the roll using an anti-friction resin bonding material, which helps the abrasive run smoothly over the workpiece. A grinding aid coating is also added to help the abrasive stay cool during grinding, minimizing heat and improving abrasive performance. This attribute, combined with the semi-flexible x-weight backing, make this roll a good match for projects that require a strong sanding tool that can be used with minimal space or leverage. Rolls can also be ordered with tapered ends. The tapered point and small size of tapered rolls enable you to get inside internal diameters and holes, making them great for deburring, blending and polishing in hard-to-reach areas. The multi-layer design of 3M Cartridge Roll 747D keeps it cutting sharp and helps it withstand repeated wear. As top layers wear down over time, underlying layers expose fresh mineral, so that you get a consistent cut on every job. Wrapping multiple layers of resin bonded abrasive material around the roll also contributes to its sturdiness and durability. The closed-coat construction means mineral grains cover 100 percent of the cloth backing, so that you get a smoother, more consistent finish. Seemingly small, these cartridge rolls conquer big challenges when space gets tight.