A clamping device for clamping a fastener, includes a clamping jaw, a first biasing member for biasing the clamping jaw, a clamping body having a central axis, a driving assembly for driving the clamping jaw to clamp the fastener, and a second member which can be driven by the first member to move axially relative to the clamping body so as to push the clamping jaw to clamp the fastener. The clamping body is formed with a notch for receiving the clamping jaw and the driving assembly is supported on the clamping body and includes a first member which can rotate and move axially relative to the clamping body. The installation structures between the clamping body, the driving assembly and the clamping jaw may be designed to be more compact so that the clamping device has a smaller size.

A chuck including a chuck body that supports a plurality of jaws. An outer sleeve is axially fixed with respect to the chuck body. A nut is coupled to the outer sleeve, and the nut is movable axially and radially relative to the chuck body. The nut interacts with the jaws such that when the outer sleeve rotates, the nut moves axially and radially relative to the body.