A ballpoint pen has a tiny ball at its tip! 🌟 When you write, the ball rolls and picks up ink from inside the pen. Then, it leaves the ink on the paper as you move it. That's how you see your writing! ✍️
It's like a little paint roller for words!
A ballpoint pen works because of a tiny metal ball (about 1mm wide) at its tip! 🔵 The ball rolls as you write, picking up ink from a reservoir inside the pen. The ink then sticks to the paper, creating smooth lines.
The ink is thick and dries quickly, so it doesn't smudge. The ball also prevents the ink from drying inside the pen by sealing it when not in use.
A ballpoint pen operates through precise engineering. Its tip contains a tungsten carbide ball (0.7–1.2 mm in diameter) that rotates freely in a socket. As you write, the ball rolls, transferring viscous oil-based ink from the reservoir onto the paper.
The ink's viscosity is crucial—it's thick enough to not leak but fluid enough to flow when the ball moves. Capillary action helps draw ink to the ball. The ball-and-socket mechanism also acts as a seal to prevent ink evaporation.
Modern pens use precise machining to ensure the ball fits perfectly with just enough space for ink flow (about 5 micrometers clearance). This is why cheap pens sometimes skip—their tolerances aren't as precise.