JINGLING 8 inch 200 mm Diamond Grinding Disc Coated Flat Lap Disk Wheel Grit 240 Medium Product Name: 8 inch diamond grinding disc, sharpen grinding disc Product Specification: Outside diameter: 8" inch (200mm) Arbor hole: 1/2" (12.7mm) Thickness: 1.3mm Grit: 240 Grit type: Medium Recommended speed:1400-2800RMP Diamond coating Density : Perfectly high Diamond coating surface area : almost 95%, only one side is coated diamond Wet use recommended Suitable to grinding gemstone, jewelry, glass, rock, etc. The diamond shape sanding discs are one of the finest discs manufactured for hobby, lapidary, glass applications The diamond flat lap wheels have a high density quality diamond coating The faceting lap is absolutely flat and parallel to meet the most exacting faceting requirements Quick Tips 1. Recommended for rough and fine grinding on faceting material plus general lapidary grinding when precision is required 2. All our flat laps wheels have a 1/2" arbor hole and are intended to be mechanically clamped to a Master Lap 3. The flat lap discs are made with 1mm thick steel plate that has been machined true and flat. The lapping plate is stiff enough to be used as is, but we recommend with the use of Aluminum Master Lap Also Available in Grits 60, 80, 100, 120, 150, 180, 240, 320, 400, 500, 600, 800,1000, 1200, 1500, 1800, 2000, 3000