Why Padlocks Have a Small Hole on the Bottom

When inspecting a typical padlock, you may notice that it has a small hole on the bottom. Padlocks, of course, are security devices. They consist of a shackle and a body. Keyed padlocks are opened with a key, whereas combination padlocks are opened by entering a combination. Whether it’s a keyed or combination padlock, though, it may feature a small hole on the bottom as well. What’s the purpose of this small hole exactly?


The small hole on the bottom of padlocks acts as a drainage port. Moisture will inevitably make its way into a padlock. If left unchecked, it may damage the padlock’s internal components, such as the tumblers. The presence of a drainage port prevents this from happening. Rather than accumulating inside of the padlock, moisture will drain out via the small hole.

Rust Prevention

Because it acts as a drainage port, the small hole on the bottom of padlocks helps to prevent rust. Padlocks, particularly industrial padlocks, are made of strong materials like zinc-plated carbon steel. While they are designed to withstand regular use, though, they aren’t immune to rust. Moisture may interact with the iron and iron-based materials from which a padlock is made, resulting in rust and corrosion.

By allowing moisture to drain out of padlocks, the small hole protects them from rust and corrosion. Moisture will drain out of the small hole while subsequently minimizing the risk of rust and corrosion.


Another reason padlocks have a small hole on the bottom is for lubrication. Padlocks contain moving parts, such as tumblers, inside of their body. Over time, some of these parts may get stuck, in which case you may struggle to open the padlock. Fortunately, a little lubrication will often resolve the problem. You can apply a small amount of lubrication through the small hole and into the padlock’s body.

Secondary Access

Depending on the specific type of padlock, the small hole may offer a means of secondary access. A locksmith, for instance, may be open the padlock by inserting a special tool into the small hole.

In Conclusion

The small hole on the bottom of padlocks serves several purposes. The main purpose is drainage. Without the small hole, moisture would build up inside of the padlock’s body, which can lead to problems like rust and corrosion. There are many different types of padlocks, but they often feature a small hole on the bottom to allow moisture to drain out of the body.