PFERD PolifanĀ® 62150 Flap Disc, Type 27 Flat, Performance Line SG, Outer Diameter: 4-1/2 Inch, Face Width: 3/4 Inch, Arbor Hole / Thread Size: 7/8 Inch A.H., Grit: 40, Max Speed: 13300 Rpm, Abrasive Type: Aluminum Oxide, Mounting: Arbor, Product / Materials Abraded: Steel, Stainless Steel (INOX), Plastics And Wood