Jacobs Chuck high torque and precision keyless drill chuck with integrated shank. CNC Machine precision chucks for drilling, boring, counter-boring and milling operations which requires heavy penetration. Arbor is integrated into the internal socket of the drill chuck. This integrated design makes it impossible for the arbor and the drill chuck to become accidently separated, providing a unit of greater rigidity and precision as a result of its compact design, accumulated run-out is reduced to a minimum. Self tightening feature automatically increases gripping force proportional to increased torque to prevent tool shank slippage. Right handed operation only. 100 percent individually controlled to ensure not to exceed a maximum total integrated run-out of 0.0016-inch. This is R8 mount. 0.630-inches maximum capacity. Measures 2-1/8-inches sleeve diameter by 3-25/32-inches closed length and 3-11/32-inches open length.