Feature:1. The grinding needle has high strength and high temperature resistance, and will not drop sand2. Using black nickel treatment, greatly improve the hardness, easier to use3. CNC milling adaptor without skipping knife, suitable for engraving machine, grinding machine, etc.4. Small size, easy to carry and store, easy to use and with good performance5. Strict quality control and quality assurance, high safety factor, can be used with peace of mindSpecification:Item Type: Grinding Needle SetMaterial: DiamondGrit Size: 150 (Grit)Shank Diameter: Approx. 3mm / 0.1inLength: Approx.45mm / 1.8inGrinding Tip Diameter: Approx. 1.5mm / 0.1in.Package List:1 x 1.5mm Grinding Needle Set(30Pcs)Note:1. When installing the grinding tip, the clamping clamp must be stable, and there must be no jumping phenomenon!2. The rotation speed is as high as possible, generally requires a linear speed of not less than 1020 meters seconds!3. This product is a 3mm handle, please check the clamping range of the machine before buying!