Item Type: Sharpener Chuck Model: 3-9mm Grinding Machine Chuck Hardness: HRC40-45 Clamping Accuracy: 0.02mm Clamping Range: Approx. 3mm / 0.12in, 4mm / 0.16in, 5mm / 0.2in, 6mm / 0.24in, 7mm / 0.28in, 8mm / 0.31in, 9mm / 0.4in Collet Total Length: Approx. 122mm / 4.8in Collet End Diameter: Approx. 20mm / 0.8in Tail Thread: M20 Tail Thread Length: Approx. 29mm / 1.1in Rod Diameter: Approx. 20mm / 0.8in Package List 1 x 5mm Chuck 1. Ensure each type of chuck is placed into the corresponding diameter tool to prevent any damage, as the tool's diameter may exceed the chuck model size. 2. When switching tools, clean any impurities inside the jacket promptly to extend the chuck's lifespan. 1. The collet features a single-piece construction with an extended total length, ideal for mounting on a knife sharpener. 2. Strong clamping force with an accuracy of 0.02mm, perfect for precision work. 3. High aperture precision, standard thread size, and minimal risk of detachment during installation and use. 4. Various size specifications offer different clamping ranges, suitable for various clamping needs. 5. Crafted from high-quality metal materials, boasting a hardness of HRC40-45, ensuring resistance to external pressure.