For sharpening, grinding, and polishing tough materials, this 180-grit diamond resin grinding wheel gets the job done. Its specifications are: 150mm (about 5.91 inches) outer diameter, with a 32mm (1.26 inch) bore hole to fit your grinder's arbor, and a 10mm (0.39 inch) thickness. Weighing around 518 grams, it has a solid, substantial feel. The resin bond matrix holds the diamond abrasive and is designed for effective material removal while generating less heat on your workpiece, which is crucial when working with carbide-tipped tools, hard steel, stone, or other metals. It's commonly used for sharpening alloy knives, saw blades, and other cutting tools. Remember, this is for one (1) wheel. Always follow proper safety procedures when using grinding wheels, including wearing eye protection and ensuring the wheel's maximum speed rating exceeds your tool's RPM. A essential accessory for workshops, fabrication, and serious DIYers.