Fastening apparatus for components, in particular cable connections or the like, in a passage recess in a wall, in particular a switchgear cabinet, having an outer face and an inner face, comprising - a main body unit with a continuous recess, wherein the main body unit, as far as an end-side stop, can be placed against the outer face of the wall, and - a fastening unit which can be arranged on the inner face, can be connected to the main body unit and by means of which the fastening apparatus can be fastened to the wall, - the fastening unit is in the form of a fastening nut, and - the fastening unit -- has a continuous recess, -- has a head region, -- has a shaft region with a thread which can be screwed into the thread of the main body unit, -- has an interlocking contour which is present at least in regions on the inner wall of the continuous recess and to which a mating interlocking contour of a turning tool, which can be inserted through the recess in the main body unit, can be connected, wherein - the head region has at least two first regions and second regions which are arranged between the first regions, wherein the distance between the outer edge contours of the first regions is greater than the cross-sectional dimension of the passage recess, and the distance between the outer edge contours of the second regions is less than the cross-sectional dimension of the passage recess, so that the head region of the fastening nut can be threaded into, passed through and engage behind the passage recess by tilting the said fastening nut, - the thread of the shaft region is in the form of an external thread and the thread of the main body unit is in the form of an internal thread, - characterized in that - there is a projection unit on the end side of the main body unit, the said projection unit, when the main body unit is fitted to the wall, protruding into the passage recess, but not protruding out of the said passage recess, and bearing against the inner wall of the passage recess. - a main body unit with a continuous recess, wherein the main body unit, as far as an end-side stop, can be placed against the outer face of the wall, and - a fastening unit which can be arranged on the inner face, can be connected to the main body unit and by means of which the fastening apparatus can be fastened to the wall, - the fastening unit is in the form of a fastening nut, and - the fastening unit -- has a continuous recess, -- has a head region, -- has a shaft region with a thread which can be screwed into the thread of the main body unit, -- has an interlocking contour which is present at least in regions on the inner wall of the continuous recess and to which a mating interlocking contour of a turning tool, which can be inserted through the recess in the main body unit, can be connected, wherein -- has a continuous recess, -- has a head region, -- has a shaft region with a thread which can be screwed into the thread of the main body unit, -- has an interlocking contour which is present at least in regions on the inner wall of the continuous recess and to which a mating interlocking contour of a turning tool, which can be inserted through the recess in the main body unit, can be connected, wherein - the head region has at least two first regions and second regions which are arranged between the first regions, wherein the distance between the outer edge contours of the first regions is greater than the cross-sectional dimension of the passage recess, and the distance between the outer edge contours of the second regions is less than the cross-sectional dimension of the passage recess, so that the head region of the fastening nut can be threaded into, passed through and engage behind the passage recess by tilting the said fastening nut, - the thread of the shaft region is in the form of an external thread and the thread of the main body unit is in the form of an internal thread, - characterized in that - there is a projection unit on the end side of the main body unit, the said projection unit, when the main body unit is fitted to the wall, protruding into the passage recess, but not protruding out of the said passage recess, and bearing against the inner wall of the passage recess.