The invention relates to a chuck (1) for tools, especially screwdriver bits with a polygonal section (2), having a polygonal cavity (3) for the insertion of the polygonal section (2), the wall (4) of the polygonal cavity (3) having a window (5) in which is disposed a pressure-piece (6) which can be displaced in the insertion direction (E) and which, in order to secure the inserted polygonal section (2) against being drawn out, is forced against the polygonal section (2), in a direction transverse to the insertion direction (E), by a sloping inner wall (9) of an actuating element which is outside the window and is retained in a clamping position by a restoring spring (10), and which, in a release position of the actuating element (7), can move aside out of the polygonal cavity (3) in order for the polygonal section (2) to be drawn out, and proposes to achieve a further development of the generic type in that the pressure-piece (6) is subjected to the action of a compression spring (8) acting counter to the insertion direction (E) and, upon displacement counter to the direction of spring action, can move aside out of the polygonal cavity (3).