Abstract: The subject matter of the invention is an electrical apparatus (1) with a screw terminal (3) for connecting electrical conductors, comprising a housing (5) with a shaft (7), in which a screw (9) with a screwdriver opening (11) is provided, which screw is surrounded radially by the shaft (7) and can be rotated in a targeted manner only via the screwdriver opening (11) thereof, wherein the screw head (15) and the shaft (7) are matched to one another in such a way that, during a rotation of the screw (9), a minimum torque is passed through in a first rotary angle range and a maximum torque is passed through in a second rotary angle range, wherein the screw head (15) has a maximum screw head diameter (D1) and a screw head diameter (D2) which is reduced in comparison therewith, wherein the shaft (7) contains a first shaft diameter (DS1) which corresponds to the maximum screw head diameter (D1), and a smaller second shaft diameter (DS2), wherein the lateral surface of the screw head (15) is curved in the region of