Feature:1. HIGH CONCENTRICITY: Made of 40Cr material, effectively suppressing vibration, possess high concentricity, and stable processing2. FINE CONTROL PROCESSING: The inside and outside of the tool holder are integrally formed. Fine control processing bring more stable performance and high concentricity3. 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 holders4. STRONGER FATIGUE RESISTANCE: Using carburizing and quenching process, the hardness is higher, the fatigue resistance of the interface is stronger and more durable5. 17MM CLAMPING RANGE: The clamping range is from 17mm, possess stable structure, excellent performance and long service life, very reliableSpecification:Item Type: Collet Chuck HolderProduct Material: 40Cr + carbon steelHardness: 45-46HRCHead Diameter: Approx. 16mm / 0.63inClamping Range: Approx. 1 ~ 7mm / 0.04 ~ 0.28inAdapter Collet: ER11Thread Type: MTool Handle Diameter: Approx. 12mm / 0.47in.Package List:1 x Collet Chuck Holder1 x WrenchNote:1. Incorrect assembly may damage the accuracy of the nut and spring.2. Only the matching collet chuck can be used to assemble the nut.3. Do not clamp tools that exceed the clamping range.