Tacking device (2, 56, 72) for at least temporarily attaching components (4, 6) to each other, having: a sleeve (10, 68, 74) having a first end, a second end, an axial hole and a collar protruding radially at the first end, an elongated mandrel (30, 64) having a head end and a tensioning end, wherein the mandrel (30, 64) can be inserted into the axial hole at the second end of the sleeve (10, 68, 74), can be brought with the head end into stop contact with a sleeve rim surface and, when inserted, projects out of the sleeve (10, 68, 74) beyond the first end, wherein a holding unit (41, 67, 78) is provided, which is designed to hold the mandrel (30, 64) when the tacking device (2, 56, 72) is inserted into an opening in a component (4, 6), wherein the sleeve (10, 68, 74) has a deformable material which is squashed against a component (4, 6) when the tacking device (2, 56, 72) is inserted into an opening in the component (4, 6) as the head end of the mandrel (30, 64) is moved in the direction of the first end of the sleeve (10, 68, 74), wherein the mandrel (30, 64) has a predetermined breaking point (36, 70) with a weakened cross section, which is positioned between the head end and the tensioning end and which is designed to ensure that as the sleeve (10, 68, 74) is squashed, the mandrel (30, 64) breaks at the predetermined breaking point (36, 70) and a section having the tensioning end is detached, wherein the holding unit (41, 67, 78) is formed by a funnel-shaped section at the first end of the axial hole and by a separate collar element (24, 58), wherein the collar element (24, 58) has a radial projection, an insertion section which extends axially and in a tapering manner from the latter, is designed to correspond to the funnel-shaped section and has a through hole for the mandrel (30, 64) to be led through, wherein at least one first engagement element running partly around an inner surface of the funnel-shaped section is arranged in the funnel-shaped section and wherein at least one second engagement element running partly around an outer surface of the insertion section is arranged on the insertion section and is designed to enter into a latching connection with the first engagement element. a sleeve (10, 68, 74) having a first end, a second end, an axial hole and a collar protruding radially at the first end, an elongated mandrel (30, 64) having a head end and a tensioning end, wherein the mandrel (30, 64) can be inserted into the axial hole at the second end of the sleeve (10, 68, 74), can be brought with the head end into stop contact with a sleeve rim surface and, when inserted, projects out of the sleeve (10, 68, 74) beyond the first end, wherein a holding unit (41, 67, 78) is provided, which is designed to hold the mandrel (30, 64) when the tacking device (2, 56, 72) is inserted into an opening in a component (4, 6), wherein the sleeve (10, 68, 74) has a deformable material which is squashed against a component (4, 6) when the tacking device (2, 56, 72) is inserted into an opening in the component (4, 6) as the head end of the mandrel (30, 64) is moved in the direction of the first end of the sleeve (10, 68, 74), wherein the mandrel (30, 64) has a predetermined breaking point (36, 70) with a weakened cross section, which is positioned between the head end and the tensioning end and which is designed to ensure that as the sleeve (10, 68, 74) is squashed, the mandrel (30, 64) breaks at the predetermined breaking point (36, 70) and a section having the tensioning end is detached, wherein the holding unit (41, 67, 78) is formed by a funnel-shaped section at the first end of the axial hole and by a separate collar element (24, 58), wherein the collar element (24, 58) has a radial projection, an insertion section which extends axially and in a tapering manner from the latter, is designed to correspond to the funnel-shaped section and has a through hole for the mandrel (30, 64) to be led through, wherein at least one first engagement element running partly around an inner surface of the funnel-shaped section is arranged in the funnel-shaped section and wherein at least one second engagement element running partly around an outer surface of the insertion section is arranged on the insertion section and is designed to enter into a latching connection with the first engagement element.