The specification describes a tool arrangement and chuck apparatus for quick change of a range of tools. In particular, a quick change chuck adapted to engage various diameter drill bits, tools and tool holders. The tools are rotatable in a chuck or adaptor and have at one end a centreing shaft portion having a constant diameter for mulitple tool end diarneters and shapes, a drive shoulder portion and a lock portion in any order. The chucks are described as haying a tool cenerting arrangement for accomodating the constant diameter centering shaft. The chucks are also described as having tool bit release mechanism operable to disengage the tool from a retention mechanism when a force is applied inwards of the body of the chuck by the user to allow the tool bit to be removed longitudinally from the chuck but also arrange to allow the tool bit to be inserted longitudinally into the chuck without requiring any other user operation.