Designed for high precise and highly-speed applications The length of the extension rod allows the milling cutter to enter the deeply cavity machining grooves for machining Hardened precise grinding Available in 5 configurations combining straight shank size (8-12mm) C8ER8A/C8ER11A/C10ER8A/C10ER16A/C12ER8A optional, the 100mm extended shaft enables deeply cavity machining while hardened precise grinding maintains <0.01mm runout for professional accuracy Engineered for high precise machining, this collet chucks extension rod features vacuum quenched 40CrMnTi alloy steel with HRC58-62 hardness and 0.01mm pulsation tolerance, ensuring most tool life and nonvibration operate in high speed applications up to 30,000RPM, Manufacturer: jklymm