Engineered for high-performance grinding and finishing, these flap discs are crafted from premium zirconia grain, ensuring exceptional durability and a superior finish. Designed specifically for steel applications, the discs feature a robust poly/cotton backing that enhances both longevity and finish strength. With a size of 4-1/2 x 5/8-11 and a grit rating of 80, they are optimized for use with high-output angle grinders, allowing for efficient material removal at speeds up to 13,300 RPM. Each box contains 10 discs, making them a reliable choice for professionals seeking consistent results in welding and metalworking tasks.