upepo
Elder Lister
- Did you know that the reason ball pen caps have a hole at the end is to prevent suffocation should the cap be accidentally lodged in the airway?
- The barrel of the pen has a smaller hole whose function is to equalize the pressure inside the pen to that outside. This allows ink to flow easily. If the pressure inside were lower than that outside, the ink would have difficulties flowing out. If the pressure inside were higher than that outside, the ink would squeezed out through the tip.
- The tip of a ball pen is the hardest material you will come across on a daily basis, hard enough to scratch metal, glass, ceramics etc. It is a ball made of tungsten carbide, whose melting temperature of 2840 degrees Celsius. You can use this tip to make markings on virtually everything around you.
- When exposed to excessive heat, such as when kept in the pocket during hot weather, the ink may warm up, become less viscous, and bleed through the tip.
- What it looks like close-up.
- How it works
