Tacking device for at least temporarily attaching components to each other, having: a sleeve having a first end , a second end , an axial hole and a collar protruding radially at the first end , an elongated mandrel having a head end and a tensioning end , wherein the mandrel can be inserted into the axial hole at the second end of the sleeve , can be brought with the head end into stop contact with a sleeve rim surface and, when inserted, projects out of the sleeve beyond the first end , wherein a holding unit is provided, which is designed to hold the mandrel when the tacking device is inserted into an opening in a component , wherein the sleeve has a deformable material which is squashed against a component when the tacking device is inserted into an opening in the component as the head end of the mandrel is moved in the direction of the first end of the sleeve , wherein the mandrel has a predetermined breaking point 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 is squashed, the mandrel breaks at the predetermined breaking point and a section having the tensioning end is detached, wherein the holding unit is formed by a funnel-shaped section at the first end of the axial hole and by a separate collar element , wherein the collar element 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 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 having a first end , a second end , an axial hole and a collar protruding radially at the first end , an elongated mandrel having a head end and a tensioning end , wherein the mandrel can be inserted into the axial hole at the second end of the sleeve , can be brought with the head end into stop contact with a sleeve rim surface and, when inserted, projects out of the sleeve beyond the first end , wherein a holding unit is provided, which is designed to hold the mandrel when the tacking device is inserted into an opening in a component , wherein the sleeve has a deformable material which is squashed against a component when the tacking device is inserted into an opening in the component as the head end of the mandrel is moved in the direction of the first end of the sleeve , wherein the mandrel has a predetermined breaking point 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 is squashed, the mandrel breaks at the predetermined breaking point and a section having the tensioning end is detached, wherein the holding unit is formed by a funnel-shaped section at the first end of the axial hole and by a separate collar element , wherein the collar element 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 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 . <EOS>