Abstract: An apparatus for deforming the end of a tube structure includes a closing tool moving in an orbital motion about the end of the tube while the tube is being advanced. The closing tool in combination with the force applied to advance the tube form the tube into the shape of the closing tool and over the internal components of the tube. The closing tool and one end of the tube can be combined in a chamber of the closing tool so that the tube end can be closed while the internal volume of the tube is pressurized. The closing tool is particularly adapted to deform the end of a tube structure of a shock absorber type device.