How to Open a Combination Safe, One Turn at a Time

Short answer: How to open a combination safe depends on who made the lock, because the direction you start and the number of turns differ. On a common Sargent & Greenleaf three-wheel lock: turn left until the first number reaches the top index the fourth time, right until the second number reaches it the third time, left until the third number reaches it the second time, then right until the dial stops. SentrySafe's fire safe manual starts to the right instead. Dial slowly, look straight at the numbers, and if you overshoot one, start over from the beginning.

This guide is for a safe you have the combination to. If you don't, skip to the locked out of a safe guide. For buying advice on dial-locked safes, see our combination safes page.

How does a combination safe work? Wheels, a gap and a bolt

Inside a mechanical safe lock is a stack of wheels. Sargent & Greenleaf's glossary says each wheel carries one number of the combination: the first wheel holds the first number, and so on. Each wheel has a cutout called a gate. Dial the right numbers in the right order and the gates line up. Then the lock's lever drops into them, and the final turn pulls the bolt back.

That's why direction and turn count matter. S&G's guide says each full turn of the dial engages another part of the mechanism, so it is normal to feel more resistance with each revolution. Skip a turn, or add one, and a wheel ends up in the wrong place.

There is a standard for these locks. UL 768 covers mechanical combination locks for safes and vaults and tests how well they resist being opened by sight, touch or hearing. It does not cover electronic locks.

How to open a dial safe: the Sargent & Greenleaf steps

Sargent & Greenleaf makes mechanical locks found on many safes. Its operating instructions for the 6730-series three-wheel lock read like this:

1. Turn the dial left (counterclockwise) until the first number lines up with the opening index for the fourth time.
2. Turn the dial right (clockwise) until the second number lines up for the third time.
3. Turn the dial left until the third number lines up for the second time.
4. Turn the dial right until it stops, at about 95. The bolt is retracted. Turn the handle.

If the dial doesn't stop, S&G says to repeat the whole procedure carefully.

The opening index is the mark at twelve o'clock on the dial ring. S&G locks also have a second mark at about eleven o'clock. That is the changing index, used only when setting a new combination. Dial to the wrong mark and the right numbers won't work.

Four numbers? S&G's troubleshooting section gives a separate sequence for four-wheel locks, starting to the right and stopping the fifth time. If your combination has four numbers, find the procedure for your lock before you dial.

Locking it again. S&G says to turn the dial four complete revolutions to any number that isn't part of the combination.

The SentrySafe fire safe version: same idea, different turns

SentrySafe's Fire-Safe owner's manual describes its mechanical dial differently:

1. Rotate the dial to 0, then turn right, passing 0 three times, and continue to the first number.
2. Turn left, go past the second number once, and stop the second time you reach it.
3. Turn right and stop at the third number.
4. Rotate the handle down to open the door.

On dual key/combination models, the manual says to turn the key to unlocked first. That key is "a secondary locking feature not an override key." You need both.

Two manufacturers, two opposite starting directions. That's the reason I won't hand you one universal procedure. Your manual's version is the one that counts. (Mine are filed by brand. I'm aware of how that sounds.)

Dialing tips from the people who make the locks

S&G's instructions list a few rules worth taping inside a cupboard door:

• Look at the dial straight on. Viewing from an angle puts the wrong number under the mark.
• Never back up. If you pass a number, start the whole sequence again from the beginning.
• Left is counterclockwise, right is clockwise. Always.
• Count each arrival. Each time your number reaches the index, that's one turn — even the first time, if it's only a few numbers away.
• Never force the dial. S&G says a dial that won't turn under light-to-moderate pressure means the lock is open or needs a qualified safe technician.

Patience is the whole technique. Speed is how you end up dialing it four times.

Safe dial stuck, or the right combination won't open it

Before you assume the combination is wrong, rule out the causes the manuals list.

• Dialing error. S&G's troubleshooting section says a very high percentage of lockouts come from improper dialing. Re-dial slowly, three times. ALOA's consumer page says the same: verify the combination by dialing it deliberately.
• Shipping screw. SentrySafe's manual lists a shipping screw still in place as a reason the dial won't turn on a new safe.
• Handle position. The same manual says to make sure the handle is all the way up in the horizontal position before unlocking.
• A tight door. For gasketed doors, SentrySafe says to hold the handle up while dialing, then pull it down.
• A shifted dial ring. S&G calls a misaligned dial ring the number one cause of lockouts. If the ring is bumped, the opening index moves, and the combination effectively changes with it.

That last one is a job for a technician. So is anything that grinds, binds or feels loose. S&G's guide claims that between 80 and 90 percent of safe lockouts can be overcome without penetrating the safe — by people who know the lock. ALOA's page points to SAVTA members for this work and warns against lubricating a safe lock yourself.

How to find your safe combination if you've lost the paper

This is the legitimate list, in order:

• The manual. SentrySafe prints the combination on the back of the owner's manual. Honeywell's FAQ says to check the first or last page for a combination sticker.
• Registration. SentrySafe's manual says registered owners can retrieve forgotten combinations. Liberty says registering creates a record of ownership it can refer to later.
• The manufacturer, with proof. Liberty requires a notarized request for unregistered safes. Other makers have their own forms.
• A licensed safe technician who verifies the safe is yours.

People also search for "common safe combinations" and how to crack a combination. This site doesn't cover either. A dial that gives way to a list of popular numbers has failed at its one job, and a published method works for anyone, not just owners. The locked out of a safe guide covers the legitimate routes.

Digital safe combination vs a dial: and switching between them

A "digital safe combination" is really a keypad code, and it works differently — see how to open a digital safe without the code. Liberty's lock comparison says keypads are faster and let owners change codes themselves. Mechanical dials need no power and take more patience.

Can you change a dial safe to digital? Liberty says most of its safes with a mechanical lock can be retrofitted with a UL-listed electronic lock, and that a professional locksmith or certified Liberty dealer can usually do it. Other brands vary. Ask the maker first.

Here's the catch: dial locks need servicing too

The pitch for mechanical dials is that they never need batteries. True. But they aren't maintenance-free.

S&G's instructions say all combination safe locks should be serviced by a qualified safe technician annually, more often in dusty or humid places. Liberty's comparison says professional servicing every few years. The two documents disagree on the interval. They agree that someone qualified should look at it, and neither suggests a can of spray lubricant. ALOA says not to lubricate it yourself.

A dial that has been getting stiffer for a year is telling you something. The lockout comes later, usually on a weekend.

Skip it if: when you don't need this guide

• You have the combination and it works. You're done. Consider writing it down somewhere other than the safe.
• You want to change the combination. That's a different procedure — see how to change a safe combination.
• Your safe has a keypad. See how to reset a safe code or the digital guide above.
• The safe is old and nobody knows the combination. See how to open an old safe.

That's the dial, explained. Find the manual for your lock, dial slowly, never back up, and if it still won't open after three careful tries, call the maker or a qualified technician before you call anyone with a drill. Then put the combination somewhere safe that isn't the safe.