POLARIS3623 Precision Diamond File Set of 10 #200 Diamond Particles Nickel Electroplated Diamond Particles. The particle of small diamonds is evenly distributed, and nickel electrodeposited into a file alloy in a stable state. Due to the synergy of the hardness of the diamond and the sharp edge of the grinding grains protruded on the surface, the cutting speed is high and the sharpness will last forever. Can be used for processing and finishing a variety of materials such as iron, non-ferrous metals, various special blades steel, glass, ceramic, resin, etc. Size: Total Length: Approx. 5.4 inches (138 mm); Grain Size: #200; Material: Carbon tool blade (body), polyvinyl chloride (handle)