Feature: 1. APPLICATIONS: This straight chuck tool holder is suitable for deep processing, used for CNC milling, drilling machines, etc., stable and reliable. 2. HIGH EFFICIENCY: The maximum speed of the chuck tool holder is 8000RPM, with high accuracy, greatly improving processing efficiency. 3. 40CR MATERIAL: The chuck holder is made of 40CR material, repeatedly tempered and forged to ensure high hardness and stable structure. 4. GLOSSY FINISH: With exquisite workmanship, the chuck holder has a glossy finish, without burrs or notches, will not scratch other parts. 5. STANDARD SIZE: The straight chuck tool holder has standard size, making it easy to install and disassemble, ensuring secure clamping. Specification: Item Type: Collet Chuck Holder Model: R8-ER40(M12) Material: 40Cr Thread Shaft: R8 Drawbar: M12 Application: For R8 special machine R40 tool holder Total Tightening Accuracy: ≤0.005 Rounding: <0.8u Body Accuracy: 0.001 Carburization Depth: >0.8mm Surface Roughness: >0.8mm Runout Tolerance: 0.0004 Minutes Standard Speed: 8000RPM. Package List: 1 x Chuck Holder1 x Storage Box Note: During testing, whether the user machine tool spindle has errors also has a significant impact on accuracy. Therefore, you need to ensure that the spindle accuracy of the user testing machine must be very high. In addition, please ensure that the accuracy of the ER collet must be very high, as many ER collets are marked as 0.0005, many of which cannot be achieved.