Product Description Multi-purpose aluminum oxide sandpaper provides excellent performance at a value price. These sheets are ideal for both hand and power tool sanding on wood, metal, fiberglass and painted surfaces. Aluminum oxide is a durable grain that is recommended by professionals for general sanding a wide variety of surfaces. From the Manufacturer Gator Grit 25 Count 9" x 11'' 50 Grit Coarse General Purpose Sandpaper. The 50 grit coarse sandpapers are designed for use on wood, metal, drywall, fiberglass and painted surfaces. You can use these sheets to sand by hand or with a machine. The sheets can also be used with an orbital sander by cutting the sheets into 1/2 sheet, 1/3 sheet or 1/4 sheet to fit your orbital sander.