Abstract: A chisel (10) comprises a handle (14), shank (12) and working bit (16). A key (80) slides longitudinally in a dovetail slot (30) and is driven by an actuator sleeve (70) which serves to draw the key (80) up the slot (30). The key (80) has a key-head (82) which engages the blade bit (16) and draws it onto a seat formed a the end of the shank (12). On the other hand, a chisel (10′) comprises a handle (14), a shank (120), and a tool bit (160), wherein the shank is a plastics moulding and the tool bit is moulded on the end of the shank. The shank and handle between them have a selectively disengageable plug (124) and socket (402).