The deformable element for absorbing kinetic energy is a plastic pipe section (1) having interior surfaces at opposite ends thereof. The plastic pipe section (1) initially deforms elastically under an applied axial force (F) and, when a yield stress limit is exceeded by the applied axial force (F), the plastic pipe section (1) deforms or collapses with an approximately equal deforming force over a work stroke until adopting a physically deformed shape in which the interior surfaces at the opposite ends contact each other. The device for absorbing kinetic energy is also described including several plastic pipe sections stacked in a column with an intermediate plate between each adjacent pair of pipe sections. The plastic pipe sections and engaged around a tubular round body for support and guidance. An inner screw bolt can also be provided for pre-tensioning the plastic pipe sections.