Padlocks are everyday items with an important job. We use them to secure bikes, sheds, toolboxes, storage units, and gates. They’re built to be sturdy, tough, and resistant to tampering — but many people never notice they also have a hidden feature: a tiny hole at the bottom.
It’s not a design flaw. It’s intentional — and it serves more than one purpose.
A Small Hole With a Big Function
Padlocks are exposed to outdoor conditions, meaning rain, snow, humidity, and dirt can all damage the inner mechanism. Because they’re made of metal, they’re especially vulnerable to rust.
That small opening at the bottom of the lock acts as a drainage hole. It allows water to escape, preventing corrosion inside the lock. Without it, moisture could get trapped and ruin the locking mechanism much faster.
In other words, that little hole is a built-in protection feature that extends the life of your padlock.
The Modern Alternative: Weatherproof Locks
Today, you can buy weatherproof padlocks designed to withstand harsh conditions. These versions often have rubber seals or protective coverings. But the tiny drainage hole remains a classic and effective feature on many standard locks.
Another Purpose for the Mystery Hole
That small opening isn’t just for drainage — it can also help when the lock gets stuck.
If a padlock is hard to open or the mechanism becomes stiff, a few drops of lubricant (like WD-40) can be applied through the bottom hole. This lets the oil reach the internal components directly, often freeing the mechanism quickly.
It’s a clever dual-purpose feature many people never knew existed.
Other Everyday Items With “Hidden Features”
Padlocks aren’t the only objects with design secrets. Many ordinary items around us have built-in features people rarely notice.
1. Screwdrivers That Double as Wrenches
Mechanics often struggle with tight or awkward spaces when repairing cars.
But most screwdrivers can be placed through the hole of a wrench to create extra leverage and reach difficult spots. This makes them a handy two-in-one tool.
2. Those Little Fabric Swatches on New Clothes
Many clothing items used to come with a tiny square of matching fabric — and some still do.
Why?
They help you match thread or materials when repairing tears
They allow you to test detergents or stain removers to see how they affect the color
They act as a sample so you don’t accidentally ruin the actual clothing
They’re essentially “test strips” for proper clothing care.
3. Brass Padlocks and Doorknobs
Ever notice how many doorknobs, railings, and locks are made of brass?
Brass has natural antibacterial properties, making it a hygienic choice for items constantly touched by many people. It reduces the spread of germs without needing additives or coatings.
4. The Arrow on the Car’s Gas Gauge
If you can never remember which side your gas tank is on, you’re not alone.
Car makers added a tiny triangle or arrow next to the gas pump symbol on the dashboard.
It points directly to the side your fuel door is on — a lifesaver at unfamiliar gas stations.
5. The “57” on Heinz Bottles
The Heinz 57 logo is iconic, but it’s not just for branding.
It marks the exact spot on the glass bottle where you should tap to get ketchup flowing smoothly. A small detail with a very practical use.