You’ve probably used one on a gym locker, a shed or a garden gate without ever turning it upside down. Underneath many padlocks, next to the keyhole or on the base, there’s a tiny hole that seems to serve no purpose. It does, and knowing what it’s for can keep your lock working for years.
In short
- The small hole at the bottom of many padlocks is mainly a drainage hole.
- It lets water and moisture escape so the internal steel parts don’t rust.
- It’s also the easiest way to lubricate a stiff lock.
- Use a dry lubricant like graphite, not WD-40 or motor oil.
A hole to let the water out
Padlocks spend their lives outdoors: in the rain, the snow, the morning dew. Water inevitably gets inside through the keyhole and around the shackle. Without an exit, it would sit in the mechanism and rust the internal parts. According to House Digest, these holes are “primarily designed for drainage,” letting water and moisture escape before they cause damage.
It’s the same idea as many small details on everyday objects that look pointless until you know their job, like the two holes in clothespins or the hole in a frying pan handle.
The secret entrance for lubricant
The same hole has a second use: it’s a direct path to the mechanism. When a padlock gets stiff or stuck, a little lubricant through the bottom hole can free it up.
But not just any lubricant. House Digest advises avoiding wet lubricants like WD-40 or motor oil, which can attract dirt and gum up the lock over time. A dry lubricant such as graphite powder, or a PTFE-based lock lubricant, is the better choice. That’s one more case where WD-40 isn’t the right tool, as we explained in what WD-40 is actually meant to be used for.
How to keep a padlock working
- Clean it regularly: wipe it with a damp cloth, use a soft toothbrush and mild soapy water for grime, then blow out dust.
- Keep the hole clear: dirt that clogs it blocks the drainage.
- Lubricate with a dry product through the hole and the keyhole.
- Outdoors, choose a weatherproof lock, often brass or aluminum, which resist corrosion better than steel, though they’re less strong.
- Look for a rubber gasket between the shackle and the body, or use a padlock cover.
Before winter
Cold makes things worse: water trapped inside can freeze and lock the mechanism. House Digest even suggests wrapping an outdoor lock in an old sock to help keep it from freezing. If yours is already frozen, don’t force the key: forcing it can damage the mechanism.
The limit
Not every padlock has this hole, and some high-security models are designed differently. A rusted lock that’s been neglected for years may be past saving: in that case, replacing it costs less than fighting with it. And if your lock guards something valuable, its strength matters more than any maintenance trick.
That’s the trick.
