That small hole in a safety pin is not just a design detail or leftover from manufacturing. It serves a practical purpose that enhances the pin’s reliability and versatility. Many people use safety pins daily without noticing this tiny feature, but it plays a key role, especially in situations involving movement, tension, or weight.

The hole allows a string, thread, or floss to pass through and be tied, creating a secondary closure. This helps prevent the pin from accidentally opening, which is especially useful in sewing, fabric work, or emergency repairs like securing bandages or torn clothing. When fabric shifts or pulls, threading something through the hole adds extra security, saving time and reducing the risk of injury or material slipping.