S&G Mechanical Dial Safe Lock Instructions

How to open and understand Sargent & Greenleaf mechanical dial safe locks.

S&G 6730
S&G 8500
Group 2 Dial

⚠️ CAUTION — Read Before Working on Your Safe Lock

Always open the safe first and keep the door open while practicing or verifying your combination. Test that you can open the lock at least 3 times with the door open before closing it. If you get locked out, drilling alone starts at $450+ depending on the safe's TL rating — and that doesn't include the repair and lock replacement, which adds another $250–$500 depending on the brand. A non-TL rated safe lockout can easily run $800 or more total for drilling, repair, and a new lock. Don't risk it.
Watch out for spring-loaded bolts. Many safes have spring-loaded locking bolts that automatically extend when the door swings shut. Before you start, open the safe door and put the lock in the locked position to retract the bolts. Look for a bolt release button on the inside edge of the door — it may be on the hinge side or the open side, depending on the model. Push it to lock the bolts in the retracted position so the door won't accidentally lock shut on you while you work.
If your dial is hard to turn, feels gritty, or the safe won't open with the correct combination — have it serviced by a safe technician now. A mechanical lock that's wearing out will eventually fail completely, and drilling a safe open is far more expensive than a planned repair or lock replacement.

About S&G Mechanical Dial Safe Locks

Sargent & Greenleaf mechanical dial combination locks are the industry standard for safes worldwide. These locks use a precision 3-number combination dialed on a rotating dial. Unlike electronic locks, they require no batteries and have no electronics — they are purely mechanical and extremely reliable.

Compatible Models	6730, 8500, 8400, 8550, Group 2 Dial Locks
Combination	3 numbers (right-left-right dialing pattern)
Power	None (fully mechanical)
Code Change	Requires professional locksmith with change key

How to Open a Mechanical Dial Lock

Standard 3-Number Dialing Procedure

Turn the dial LEFT (counterclockwise) at least 4 full turns to clear the lock.
Continue turning LEFT and stop on the FIRST number of your combination.
Turn the dial RIGHT (clockwise), passing the SECOND number once, then stop on it the second time around.
Turn the dial LEFT (counterclockwise) and stop directly on the THIRD number.
Turn the handle to retract the bolts and open the safe.

⚠️ Be precise — if you go past a number, do NOT back up. Start over from the beginning with 4 full left turns.

Dialing Tips

Always start by turning LEFT at least 4 full revolutions to completely clear the wheels.
Approach each number slowly and carefully — precision matters.
If you overshoot a number, even by one tick mark, start the entire sequence over.
Do not apply pressure to the safe handle while dialing the combination.
The dial should turn smoothly. If it feels gritty or stiff, the lock may need professional servicing.

Changing the Combination

⚠️ Professional Locksmith Required

Changing the combination on a mechanical dial safe lock requires a special change key specific to your lock model. This is NOT a do-it-yourself procedure. The change key is inserted into the back of the lock (inside the safe door) while following a precise dialing sequence.

Attempting to change the combination without proper tools and training can result in the lock being permanently disabled, requiring drilling and replacement.

Common Issues

Combination doesn't work: Dial more slowly and precisely. Make sure you're going the correct direction (Left-Right-Left) and counting pass-throughs correctly.
Dial feels loose or wobbly: The set screw on the dial ring may be loose, or the dial may need to be re-seated on the spindle.
Handle won't turn after correct combination: The bolt work may be jammed or the relocker may have engaged. Do NOT force it — call a professional safe technician.
Forgot combination: A locksmith with the correct tools can manipulate or drill the lock. Some S&G locks have a factory combination recovery option through the safe manufacturer.

When to Call a Professional

Mechanical dial safe locks are precision instruments. Contact Key-En-Lock for professional service when you need to:

Change the combination on your safe
Repair or replace a worn dial or spindle
Open a safe when the combination is lost or forgotten
Upgrade from a mechanical dial to an electronic lock
Service or rebuild an existing mechanical lock

Manufacturer Documents

📄 Official Sargent & Greenleaf Support & Manuals

Frequently Asked Questions

How do I dial a mechanical safe combination?

Turn left (counterclockwise) at least 4 full turns to clear, then stop on the first number. Turn right (clockwise), pass the second number once and stop on it the second time. Turn left and stop directly on the third number. Then turn the handle to open.

Can I change the combination on a mechanical safe dial myself?

No. Changing the combination on a mechanical dial safe lock requires a special change key specific to your lock model, inserted from inside the safe door. This must be done by a trained locksmith or safe technician to avoid damaging the lock.

What should I do if I forgot my mechanical safe combination?

Contact the safe manufacturer first — they may have the original combination on file if the safe was registered. If not, a professional safe technician can attempt manipulation (a non-destructive technique) or drilling as a last resort. Never attempt to force the safe open.

Why won't my mechanical safe dial open even with the correct combination?

Common causes include: dialing too fast, overshooting a number (never back up — start over), applying pressure to the handle while dialing, or the bolt work being jammed. Make sure you're turning the correct direction at each step and dialing precisely.

Need More Help?

If these instructions didn't solve your issue, contact the manufacturer directly or call your local locksmith:

📞 Sargent & Greenleaf Support 1-800-826-7652 Mon-Fri 8am-5pm ET

🔧 Key-En-Lock Locksmith (321) 224-5625 Brevard County, FL · Available 24/7

Can't reach the manufacturer? Our licensed safe technicians service all S&G models throughout Brevard County.