A resin fiber disc is much like a grinding disc made from abrasive cloth or paper. It differs principally in its strong heavy duty backing material. Under most circumstances resin fiber discs will greatly outlast their cloth or paper equivalents. Click for Product Info on PDQ Mounting System for Resin Fiber Discs. Spiralcool pads for Resin Fiber Discs Resin Fiber Discs Currently we carry five specifications of resin fiber discs, in the following sizes and grits. Other size/grit combinations are available on a special order basis. Premium Grade Aluminum Oxide (most commonly ordered)   Size: Diameter: 4" x Center Hole: 5/8"     Grits: 120, 100, 80, 60, 50, 36, 24, 16   Size: Diameter: 4" x Center Hole: 7/8"     Grits: 120, 100, 80, 60, 50, 36, 24   Size: Diameter: 4-1/2" x Center Hole: 7/8"     Grits: 120, 100, 80, 60, 50, 36, 24   Size: Diameter: 5" x Center Hole: 7/8"     Grits: 120, 100, 80, 60, 50, 36, 24, 16   Size: Diameter: 7" x Center Hole: 7/8"     Grits: 180, 120, 100, 80, 60, 50, 36, 24, 16   Size: Diameter: 9-1/8" x Center Hole: 7/8"     Grits: 80, 60, 50, 36, 24, 16 General Purpose Grade Aluminum Oxide   Size: Diameter: 4" x Center Hole: 5/8"     Grits: 80, 60, 50, 36, 24   Size: Diameter: 4" x Center Hole: 7/8"     Grits: 80, 60, 36   Size: Diameter: 4-1/2" x Center Hole: 7/8"     Grits: 80, 60, 50, 36, 24   Size: Diameter: 5" x Center Hole: 7/8"     Grits: 80, 60, 50, 36, 24   Size: Diameter: 7" x Center Hole: 7/8"     Grits: 100, 80, 60, 50, 36, 24 Premium Grade Zirconia Alumina (strongest product)   Size: Diameter: 4-1/2" x Center Hole: 7/8"     Grits: 80, 60, 36   Size: Diameter: 5" x Center Hole: 7/8"     Grits: 80, 60, 50, 36, 24   Size: Diameter: 7" x Center Hole: 7/8"     Grits: 80, 60, 50, 36, 24, 16   Size: Diameter: 9-1/8" x Center Hole: 7/8"     Grits: 50, 36 General Purpose Zirconia Alumina   Size: Diameter: 4-1/2" x Center Hole: 7/8"     Grits: 80, 60, 36   Size: Diameter: 5" x Center Hole: 7/8"     Grits: 80, 60, 50, 36, 24   Size: Diameter: 7" x Center Hole: 7/8"     Grits: 80, 60, 50, 36, 24 Premium Grade Silicon Carbide   Size: Diameter: 5" x Center Hole: 7/8"     Grits: 80, 60, 36, 24   Size: Diameter: 7" x Center Hole: 7/8"     Grits: 60, 36, 24