What is the small hole in the safety pin for?

It's something we all have at home. In a sewing kit, at the bottom of a drawer, or tucked into a bag, "just in case." The safety pin, this simple yet useful little accessory, is one of the unsung heroes of everyday life. But have you ever noticed that little hole near its spring? No? It's not surprising; it easily goes unnoticed.
And yet... this barely visible detail hides a surprisingly ingenious manufacturing secret. Ready to reveal this little hole that changes everything?

A detail that goes unnoticed... but makes the difference

Imagine: you close a safety pin and click! That perfect tension, that reassuring little "click"... This ease of use is due to a small design element:   the famous little hole near the spring  .

Located right next to the spiral mechanism, it appears purely decorative. But it actually   plays a key role in the assembly and performance of the pin  . It's neither a flaw nor an aesthetic addition, but a subtle engineering detail that ensures its proper functioning.