Ballpoint Pens: The Barrel VentWhy your pen would stop working without it.
From the show
Why it looks like thatDiscover the critical role of the tiny vent hole found on standard ballpoint pen barrels. This small aperture is an engineering necessity that equalizes atmospheric pressure, preventing a vacuum from forming inside the tube as ink is used. Without this simple vent to let air in, the ink would refuse to dispense, rendering the pen useless.
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