Ever locked yourself out and just stood there staring at your key safe, willing it to open? Turns out, on a lot of cheap combination key safes, there's a way in that doesn't involve a locksmith, a drill, or any special gear. Just a strip of paper, a pen, and a little patience.

 

It's not some closely guarded locksmith secret, either. It's a pretty well-known weak point in how cheap combination locks are built. Worth knowing about, not so you can go break into someone's stuff, but so you actually know how much protection (or how little) your key safe is giving you.

 

Why This Works: The Mechanics Behind the Trick

 

Before getting into the how, it helps to know what's actually going on inside the lock.

 

Each number on a combination key safe has its own wheel. What you see and turn from the outside is the outer ring, it's got notches for each digit and spins freely around a central axle. Tucked inside the lock body, out of sight, sits a second, smaller wheel attached to that same axle. And here's the key detail: that inner wheel isn't a perfect circle. It's got one flat section machined into it.

That flat spot is really the whole trick. Once every wheel's flat spot lines up at the same time, a bar can drop into the gaps, and the lock pops open. So the "combination" is basically just the rotation needed to get all those flat spots pointing the same way.

Which means you don't have to guess through thousands of number combos. You just need to find one thing per wheel, where that hidden flat spot is sitting. Do that for each wheel, and you're most of the way there.

 

Feeling for the Flat Spot with a Strip of Paper

 

This is where the paper comes in. There's a small gap between each wheel and the lock's outer casing, and you can slide a thin strip of paper right down into it. Press down gently, and the edge of the paper rides along the wheel's surface as you go.

 

Most of the time it'll stop pretty quickly, that's the round part of the wheel. But rotate it to the exact spot where that internal flat section is, and suddenly there's more room. The paper drops noticeably further.

 

To actually see that difference happening, draw a small line on the paper a little ways in from the tip, about half a centimeter. Then, as you press down at each position, you're watching for that line to dip below the top edge of the wheel. When it does, that's your flat spot.

 

The Basic Process, Step by Step

 

1. Cut a paper shim. About 1 cm wide, 4 cm long. Doesn't need to be exact.
2. Mark a guideline. A line across the strip, roughly half a centimeter from one end, this is what you'll be watching.
3. Insert the strip. Slide it into the gap next to one wheel, pressing down gently. Go easy, press too hard and you'll crease or wear down the paper's edge, which throws off your readings.
4. Turn the wheel one number at a time, checking the paper after each turn.
5. Watch for the drop. Once the line sinks below the top of the wheel, you've found that wheel's flat spot, note the number.
6. Do the same for every wheel on the lock.
7. Offset the numbers. Here's the catch: on a lot of these locks, the flat-spot numbers you just found aren't the actual code. You turn each wheel a fixed number of positions from there to land on the real combination.
8. Punch in the real combination, and you're in.

 

With a little practice this goes pretty fast, a few minutes a wheel, sometimes quicker.

 

What to Look for When Choosing a Key Safe

 

Not every key safe is built the same, and the details actually matter. Some things worth checking before you buy one:

 

• Wheel construction. A better-built key safe uses wheels designed to resist exactly this kind of decoding, no easily detectable flat spot or telltale gap to feel for.
• Independent security ratings. Certifications from a recognized body (Sold Secure, for example) mean the lock's actually been tested against tampering, not just assumed to hold up.
• Electronic or keypad options. These skip the mechanical wheel entirely, which sidesteps this whole style of attack.
• Solid housing and mounting. Even the best lock mechanism doesn't matter much if the box itself can be pried off the wall, the hardware and casing need to hold up too.

 

Spending a bit more upfront on a well-made, properly rated key safe buys you a kind of peace of mind that the bargain option just can't match.

 

Watch It in Action

 

Reading through the steps is one thing, seeing it done makes it click a lot faster. There's a video that walks through the whole process on a real key safe, from sliding the paper in to reading the final combination:

The Bottom Line

 

This paper-shim trick is a good reminder that combination locks aren't all created equal. If you're trusting a key safe with something that actually matters, your house keys included, it's worth doing a little homework and picking one built with quality wheels, solid hardware, and a real security rating, instead of just grabbing whatever's cheapest.