Padlocks are everyday objects we barely notice, quietly securing sheds, bikes, gates, and toolboxes. “If you look closely at the bottom of a padlock, you’ll see a tiny hole—easy to miss, yet essential to the lock’s function.”

This small hole helps padlocks survive the elements. Rain, snow, and humidity can cause metal to rust and jam. The hole “provides a drainage point, allowing trapped water to escape and preventing long-term damage.”

The hole also allows maintenance. Dirt, grit, or cold weather can make a lock stiff. “The opening allows lubricants like graphite powder or lock oil to reach the internal tumblers,” which can restore smooth movement and save a lock from being cut off.

Even modern weatherproof locks keep this feature. Rubber coatings and seals help block moisture, but engineers include the hole as a “pressure release point and backup drainage channel.” This shows how simple design choices endure because they work.

Other everyday objects have similar hidden features. Screwdrivers may have a square base to fit a wrench for extra torque. Fabric swatches on clothing once helped stores test detergents. Brass doorknobs are “naturally antimicrobial, killing bacteria on contact.” Cars hide tiny arrows on fuel gauges to indicate the gas tank side. These small details often have a big impact.