End balls for round tubing—two types. The spherical tube knob for hammering in covers tubes with diameters of 33.7 to 60.3 mm and a maximum wall thickness of 3.5 mm, and features a ball with a diameter of 40 to 60 mm mounted on a flange. The tube end ball plugs tubes with diameters from 26.9 to 60.3 mm with a ball diameter of 40 to 90 mm. A clean tube end instead of an open edge.