1、HIGH CONCENTRICITY: Made of 40Cr material, effectively suppressing vibration, possess high concentricity, and stable processing 2、FINE CONTROL PROCESSING: The inside and outside of the tool holder are integrally formed. Fine control processing bring more stable performance and high concentricity 3、FOR HIGH ACCURACY MACHINE TOOL PROCESSING: After inner hole ground treatment, suitable for high accuracy machine tool processing and has a longer life than ordinary tool holders 4、STRONGER FATIGUE RESISTANCE: Using carburizing and quenching process, the hardness is higher, the fatigue resistance of the interface is stronger and more durable 5、1‑7MM CLAMPING RANGE: The clamping range is from 1‑7mm, possess stable structure, excellent performance and long service life, very reliable Item Type: Collet Chuck Holder Product Material: 40Cr + carbon steel Hardness: 45-46HRC Head Diameter: Approx. 16mm / 0.63in Clamping Range: Approx. 1 ~ 7mm / 0.04 ~ 0.28in Adapter Collet: ER11 Thread Type: M Tool Handle Diameter: Approx. 12mm / 0.47in 1 x Collet Chuck Holder 1 x Wrench