A screw spindle pump having a spindle housing, in which a drive spindle and at least one running spindle which meshes therewith are received in spindle bores, an outer housing which encloses the spindle housing, and a cover component which is placed axially onto the outer housing and on which both an axial fluid inlet port and a lateral fluid outlet port are provided, wherein the fluid inlet port communicates with a fluid inlet of the spindle housing and the fluid outlet port communicates with a fluid outlet of the spindle housing, wherein the cover component is fastenable to the outer housing in a plurality of marked rotational positions with a first pitch, and wherein the spindle housing is fastenable to the cover component and/or in the outer housing in a plurality of marked rotational positions with a second, smaller pitch.