Item Type: Sharpener Chuck_x000D_Model: 3-9mm Grinding Machine Chuck_x000D_Hardness: HRC40-45_x000D_Clamping Accuracy: 0.02mm_x000D_Clamping Range: Approx. 3mm / 0.12in, 4mm / 0.16in, 5mm / 0.2in, 6mm / 0.24in, 7mm / 0.28in, 8mm / 0.31in, 9mm / 0.4in_x000D_Collet Total Length: Approx. 122mm / 4.8in_x000D_Collet End Diameter: Approx. 20mm / 0.8in_x000D_Tail Thread: M20_x000D_Tail Thread Length: Approx. 29mm / 1.1in_x000D_Rod Diameter: Approx. 20mm / 0.8in 1The collet is integrally formed with a long total length and is suitable for installation on a knife sharpener. 2The clamping force is strong, and the clamping accuracy is 0.02mm, which is suitable for fine operation. 3The accuracy of the aperture is high, the thread size is standard, and it is not easy to fall off during installation and use. 4Different size specifications have different clamping ranges, which are suitable for different clamping situations. 5Made of high-quality metal materials, the hardness is HRC40-45, and it is not easy to be squeezed by the outside world.1 x 3mm_x000D__x000D_Chuck