A vehicle seat frame provides a tilting feature for tilting the seat cushion. The frame includes side brackets (20) with a torsion tube (60) laterally-extending through an aperture (100) of the side brackets. The torsion tube is fitted against the side bracket through an internal swaging procedure to allow smooth rotation of the torsion tube within the side brackets. The torsion tube includes an annular protrusion (200) which provides an axial locking feature that tightly secures the subcomponents placed onto the torsion tube during vehicle operation.