We gave these discs a load resistant coating to increase efficiency and product life by minimizing loading. The abrasive is resin-bonded and supports disc flexibility without sacrificing durability and reliable performance under high heat and pressure. To complement the effective abrasive action, the polyester film backing flexes to help achieve a consistent finish over contours and offers greater tear-resistance than comparable paper products, making it ideal for high-production environments. And the 3M™ Hookit™ attachment and removal system holds the disc securely during use and provides easy disc change out. Designed for use with orbital and random orbital sanders, this disc comes in a range of grades for complete multi-step sanding and finishing. Our 3M™ Hookit™ Microfinishing Film Disc 366L features precision, micron-graded aluminum oxide, which 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 in grinding applications in addition to sanding and finishing applications. Aluminum oxide is suitable for a wide variety of materials in both woodworking and metalworking, including ferrous alloys. Whether the job requires a random orbital or rotary sander, buffer, grinder, drill, finishing sander or other power tool, hook-and-loop products allow the operator to focus more on the task and less on tooling. Abrasive products with hook-and-loop backing, including 3M™ Hookit™ products, are manufactured with loop material that attaches to a backup pad, sold separately, where tiny hooks firmly engage the loops. Attachment is quick, easy, and secure during use. Sanding, finishing, and surface conditioning products with the hook-and-loop attachment and removal system provide an efficient way to work through multi-step finishing processes and can be used again and again for the life of the abrasive. Our 3M sanding discs come in a variety of forms to fit various power tools and disc pads. Hook and Loop sanding discs are designed to be used with a random orbital sander, a handheld sanding machine that rotates the disc in a random pattern to prevent swirl marks from forming on the surface of the workpiece. The sander is fitted with a backup pad (sold separately) to which the sanding disc is attached. Hook-and-loop discs are quick and easy to change when switching from one grade to another, and can be reused again and again until worn out; whereas adhesive-backed discs are typically discarded after one use because the adhesive backing will not re-adhere a second time.