SuperGrindz 4-1/2" Trimmable Zirconia Flap Discs with threaded 5/8"-11 hub are ideal for surface blending, beveling, grinding, deburring, edge chamfering and finishing applications. The 5/8”-11 threaded hub allows for easy quick change, spin-on and spin-off action. The flap disc is made from premium European Zirconia Abrasive. Each flap disc will provide you with fast, smooth grinding and long life due to the high density 90 flap count* (as compared to standard density of 75 flaps) with trimmable backing feature. The flap discs are made with a durable polyurethane backer to handle high pressure, while providing a smooth grind with minimal vibration. Recommended to be used with angle grinders sized 4-1/2” to 5” having a 5/8"-11 threaded arbor. With Pro-Graad SuperGrindz 4-1/2" x 5/8"-11 Type 27 High-Density Zirconia Trimmable Flap Discs, you can achieve stock removal, weld blending, and surface finishing in a single step. This means that you can save time and effort by completing multiple tasks with one disc, making your work more efficient and streamlined.