The invention relates to a hydraulic expansion chuck with a basic body, with an expansion bush which is received in the basic body and defines a reception space for a tool to be chucked, and with a pressure chamber which is delimited between the expansion bush and the basic body, at least one solder region being provided, in which the expansion bush is soldered to the basic body, wherein, between the pressure chamber and the solder region, a seal is provided which is formed by an at least essentially fluid-tight bearing contact of the expansion bush against the basic body.