A screw-spindle pump stage having a drive spindle and a running spindle which runs opposite the drive spindle and a pump housing for receiving the two screw spindles. The pump housing 16 has an offset interface with centering action, for a statically determined coupling to an electric motor. The pump housing has an offset section functioning as an abutment, which is able to be abutted against the electric motor for the application of an axial preload. At least one pressure region of the abutment section, which is close to the interface and, during a rolling, is encapsulated, and at the same time sealingly enclosed, by a sheet-metal casing, forms a rolling region of the pump, the screw spindles, together with the associated pump housing section, at least partially project from the rolling region of the pump on the suction side.