Item Type: Collet Replacement Model: 1/2, 1/4, 1/8in Grinding Machine Chuck Hardness: HRC40-45 Clamping Accuracy: 0.02mm Clamping Range: Approx. 3.175mm / 0.1in, 6.35mm / 0.3in, 12.75mm / 0.5in 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 1/2-12.75mm Collet 1. Put each type of chuck into the corresponding diameter tool to avoid damage to the chuck because the diameter of the tool exceeds the size of the chuck model.2. When changing tools, clean up the impurities inside the jacket in time to ensure the service life of the chuck. 1Mount the chuck on the tool of the corresponding diameter, which can be well matched with the hand tool. 2The clamping force is strong, and the clamping accuracy is 0.02mm, which is suitable for fine operation. 3Made of high-quality materials, the hardness is HRC40-45, which is not easy to squeeze and wear. 4The collet size is standard, the thread is accurate, and it is not easy to fall off after installation. 5The collet is integrally formed with a long total length and is suitable for installation on a knife sharpener.