Axial ball bearings for Weld-on hinges—they absorb the vertical load of the door leaf and make it run noticeably more smoothly. Four sizes for pin diameters of 11, 12, 14, and 20 mm: outer diameter 19 to 32 mm, height 7.2 to 8.2 mm. Galvanised. The ball bearings are placed between the roller halves of the hinge.