An exemplary embodiment of a high speed spindle for rotating a tool at high rotational rates includes a hollow spindle body and a cylindrical spindle shaft configured for rotation within the spindle body and having a front end and a rear end. The spindle shaft includes a front hollow region and a rear hollow region. A motor is configured to impart rotational drive forces to the spindle shaft during operation. The spindle shaft includes a thrust bearing flange disposed intermediate the front end and the back end of the spindle shaft. A front air bearing and a rear air bearing are configured to radially support the spindle shaft for high speed rotational movement. A thrust air bearing is disposed between the front air bearing and the rear air bearing within the spindle housing and configured to act on the thrust bearing flange of the spindle shaft to constrain axial movement of the spindle shaft within the spindle housing. A collet is disposed within the front hollow region of the spindle shaft. An exemplary embodiment of a collet involves a centrifugal collet of unitary sleeve structure and having a plurality of flexures and weights.