A chuck for use with a manual or powered driver having a rotatable drive shaft, the chuck comprising: a body configured to rotate with the drive shaft and having an axial bore formed therein centered about an axis of the body; a plurality of first teeth rotationally fixed to the body; a plurality of jaws movably disposed with respect to the body in communication with the axial bore an annular nut having threads formed thereon in engagement with threads on the jaws, so that rotation of the nut about the body and the axis in a closing direction moves the jaws toward the axis and rotation of the nut about the body and the axis in an opening direction, opposite the closing direction, moves the jaws away from the axis; a spring assembly comprising a first annular spring rotationally fixed to the nut and having a body that biases a first distal end of the first annular spring in a radial direction with respect to the axis and that extends over an angular width about the axis that is greater than 180° in a plane perpendicular to the axis, and wherein the first annular spring defines at least one second tooth at the first distal end opposing the first teeth, and a second annular spring rotationally fixed to the nut; a hand actuatable sleeve that surrounds the body P, the first annular spring, and the second annular spring about the axis and that engages the nut so that the sleeve rotationally drives the nut in the opening and closing directions and so that the sleeve is rotatable with respect to the nut over a limited arc between first and second relative rotational positions, wherein the sleeve defines a cam surface that engages the first spring so that in the first relative rotational position between the sleeve and the nut, the first teeth and the at least one second tooth are disengaged and so that in the second relative rotational position between the sleeve and the nut, the first teeth and the at least one second tooth are engaged, and wherein the first teeth and the at least one second tooth are configured so that engagement of the first teeth and the at least one second tooth prevents relative rotation between the nut and the body in the opening direction, wherein the sleeve defines a notch that engages the second spring so that in the second relative rotational position between the sleeve and the nut, the notch receives the second distal end so that the notch resists relative rotational movement between the sleeve and the second spring in the opening direction, and wherein the second annular spring has a body that biases a second distal end of the second annular spring in a radial direction with respect to the axis and that extends over an angular width about the axis that is greater than 180° in a plane perpendicular to the axis. a body configured to rotate with the drive shaft and having an axial bore formed therein centered about an axis of the body; a plurality of first teeth rotationally fixed to the body; a plurality of jaws movably disposed with respect to the body in communication with the axial bore an annular nut having threads formed thereon in engagement with threads on the jaws, so that rotation of the nut about the body and the axis in a closing direction moves the jaws toward the axis and rotation of the nut about the body and the axis in an opening direction, opposite the closing direction, moves the jaws away from the axis; a spring assembly comprising a first annular spring rotationally fixed to the nut and having a body that biases a first distal end of the first annular spring in a radial direction with respect to the axis and that extends over an angular width about the axis that is greater than 180° in a plane perpendicular to the axis, and wherein the first annular spring defines at least one second tooth at the first distal end opposing the first teeth, and a second annular spring rotationally fixed to the nut; a hand actuatable sleeve that surrounds the body P, the first annular spring, and the second annular spring about the axis and that engages the nut so that the sleeve rotationally drives the nut in the opening and closing directions and so that the sleeve is rotatable with respect to the nut over a limited arc between first and second relative rotational positions, wherein the sleeve defines a cam surface that engages the first spring so that in the first relative rotational position between the sleeve and the nut, the first teeth and the at least one second tooth are disengaged and so that in the second relative rotational position between the sleeve and the nut, the first teeth and the at least one second tooth are engaged, and wherein the first teeth and the at least one second tooth are configured so that engagement of the first teeth and the at least one second tooth prevents relative rotation between the nut and the body in the opening direction, wherein the sleeve defines a notch that engages the second spring so that in the second relative rotational position between the sleeve and the nut, the notch receives the second distal end so that the notch resists relative rotational movement between the sleeve and the second spring in the opening direction, and wherein the second annular spring has a body that biases a second distal end of the second annular spring in a radial direction with respect to the axis and that extends over an angular width about the axis that is greater than 180° in a plane perpendicular to the axis.