A chuck device for holding an unmodified, circumferentially round tool shaft or collet includes an annular head portion having a distal end surface, a laterally spaced coupling end section, an outer circumferential surface, and a central longitudinally extending bore with an inner circumferential bore surface to slidingly receive the tool shaft or collet with the tool axis aligned collinearly with the bore axis. The head portion includes a first slot extending inwardly on one side of the annular head and normal to the distal end surface, and a second slot extending from the outer circumferential surface normal to and intersecting the first slot to form stationary and pivotable segments having a bore-facing, tool grasping surface that radially directs a compressive grasping force in an amount sufficient to hold the tool with a slip-torque of up to about 430 inch-lbs. at a rotational speed of up to at least about 20,000 rpm.