This Aluminum Master Base Plate is designed as a machine accessory, acting as a backer disc that fits into the grinding machine, providing a flat surface for attaching grinding papers, discs, or pads. This Master Base Pad is suitable for use with grinding and polishing machines. Made from aluminum, this base plate features premium workmanship, accurate dimensions, and a smooth finish. The edges are deburred to prevent hand injuries and ensure comfortable handling. Material: Aluminum. Please note: This aluminum backer disc does not have diamond coating and cannot be used for direct grinding of stone, knives, gemstones, wood, or other materials. A diamond-coated flat lap disk grinding wheel can be mounted onto this aluminum base plate. To sharpen gemstones or steel knives, a separate diamond disk must be purchased and attached to the aluminum base. Product Name: Aluminum Disc Master Base Lap Plate Product Size: Diameter: 6 inches (150mm), Arbor Hole: 1/2 inch (12.7mm) All diamond flat lap wheels with a 1/2 inch arbor hole are designed to be mechanically clamped to this aluminum plate. The surface is smooth with good concentricity. We recommend using this aluminum plate with diamond-coated flat lap disks. Note: Please verify compatibility with your equipment before ordering. Color: Silver Package Contents: 1 x Aluminum Base Plate The package includes only the items listed above; other accessories are not included. Note: Lighting effects and display settings may cause slight color variations between the image and the actual product. Measurement tolerances are +/- 1-3 cm.