Abstract: The invention relates to a hydraulic expanding chuck (1) having a main body (2) and an expanding bush (3), which is inserted into the main body (2) to form at least one pressure chamber (5a, 5b) and is intended for chucking a tool. The expanding bush (3) has a radial opening (20), which is arranged in alignment with a driver (21) which is held adjustably in the main body (2) and can be moved via the opening (20) into positive engagement with a driving surface (22) on the tool shank of a tool to be received in the expanding bush (3). According to the invention, the driver (21) has a driver screw (23), which can be driven from radially outside the hydraulic expanding chuck (1) and is screwed into a threaded bore (24) formed in the main body (2) in alignment with the radial opening (20).

Abstract: The invention relates to a hydraulic expanding chuck (1) having a main body (2) and an expanding bush (3), which is inserted into the main body (2) to form at least one pressure chamber (5a, 5b) and is intended for chucking a tool. The expanding bush (3) has a radial opening (20), which is arranged in alignment with a driver (21) which is held adjustably in the main body (2) and can be moved via the opening (20) into positive engagement with a driving surface (22) on the tool shank of a tool to be received in the expanding bush (3). According to the invention, the driver (21) has a driver screw (23), which can be driven from radially outside the hydraulic expanding chuck (1) and is screwed into a threaded bore (24) formed in the main body (2) in alignment with the radial opening (20).