when you need it most.
Essentially, the hole acts as a kind of “starting point” for the coil—a small but crucial anchor that ensures the tension in the spring is preserved. Every time you open and close a safety pin, the spring mechanism relies on this precise tension to allow smooth operation. The pin snaps back into place effortlessly because of the stability provided by the hole, demonstrating a level of design foresight that often goes unnoticed in such a humble tool.
The Engineering Behind the Tiny Hole
For those
