Different Shapes More Efficient - Made into a 10mm bullet shape, these grinding wheels for drill fit into tight spaces. Ideal for sanding after beveling holes in metal and wood. The 10mm and 15mm cylinder shapes are ideal for smoothing, sharpening, deburring, and other grinding and shaping needs. Sturdy and Durable - The hardness is similar to white corundum. The grinding stones for drill can be cleaned and restored after long-term use. They are stronger, sharper, and more durable. Wide Compatibility - Suitable for sharpening lawn mower blades, screwdriver tips, knives, scissors, chisels, and other cutting tools. Aluminum oxide sanding bits are commonly used in metalworking, such as grinding, cutting, and deburring steel, aluminum alloys, and other materials. They are also used for polishing and grinding weld points on metal castings, rust removal, and sharpening screwdriver tips. WARM TIP - For your safety, please wear appropriate safety equipment such as a face shield (or full coverage goggles) and gloves. Use light pressure; excessive force may cause the grinding stone to break. What You Get - 14 pieces of 10mm bullet shape, 14 pieces of 10mm cylinder shape, and 14 pieces of 15mm cylinder shape sanding bits. Color: As shown Material: Alumina Package Contents: 42 Pieces Grinding Bits Note: Light reflection and different displays may cause slight color variations between the image and the actual item. Measurement may vary by +/- 1-3 cm. Only the above package content is included; other products are not part of this sale.