How to Open a Locker Combination Lock? | The Correct Three-Step Sequence

A locker jammed shut minutes before class starts is a special kind of panic. The problem almost never is a broken lock — it is a missed step in the dance the lock expects. Here is the exact procedure that works on standard Master Lock models like the 1500D, 1630, and 1676, and what to do when it does not cooperate.

What Is The Correct Dialing Sequence?

The official Master Lock combination tutorial lays out a four-step process. Each step is deliberate: you are not just landing on numbers — you are setting internal discs in the right order. The indicator mark (a small red line or arrow near the dial) is your target for each stop. If your lock has a larger silver body, a slight variation applies after step three.

1. Reset the mechanism. Turn the dial three full rotations clockwise (to the right), stopping when the first number of your combination lines up with the indicator. The three full turns clear any previous partial rotation from the previous open session.
2. Set the second number. Turn the dial one full revolution counter-clockwise (to the left), passing your first number entirely. Keep turning and stop when the second number aligns with the indicator. This “pass” is the most commonly missed step.
3. Set the third number. Turn the dial clockwise (to the right) straight to the third number. Do not pass it — stop when the number hits the indicator.
4. Open the lock. Pull upward on the shackle (the U-shaped metal bar). For locks with a larger silver body, turn the dial counter-clockwise until it stops before pulling.

Built-in locker models like the Master Lock 1630 follow the same sequence: dial right two or more revolutions to the first number, left one full turn past the first to the second, right to the third, then let go and lift the door handle.

The Most Common Mistake And How To Fix It

The number one reason a lock refuses to open is skipping the full counter-clockwise revolution at step two. If you turn left only as far as the second number without passing the first, the internal tumblers never engage. Start over. Dial right three times to mark zero, then deliberately pass the first number on the left turn — go a full rotation beyond it — and land on the second number from the far side.

Other frequent errors are easier to avoid. Do not pull upward on the shackle while dialing — that tension jams the internal discs. The numbers do not have to hit the indicator line perfectly; being within roughly two numbers in either direction still works because the lock’s mechanical tolerances account for slight overshoot. And always start from the beginning if your sequence is interrupted. Dialing the numbers in the wrong order (your combination might read 25-14-36, not 14-36-25) also guarantees a stubborn lock.

If your combination was lost, Master Lock can provide a replacement key or assist if you have the lock model number, serial number, and facility name. Never force the lock — it may damage the warranty seal.

For a permanent solution, choosing a reliable combination lock for your gym locker ensures you start with a lock that matches your needs and preferences.

What About Factory Combinations And Resetting?

Most standard dial locks ship with a factory combination of 0-0-0 for three-digit models and 0-0-0-0 for four-digit variants like the Master Lock 1550 backpack lock. The reset process depends entirely on the specific model.

The reset tool that came in the original packaging is required — without it, the combination cannot be changed without professional assistance.

Checklist For A Lock That Will Not Open

Stand at the locker with the lock in hand and run through this sequence in order. Most jams resolve before step three.

1. Is the dial on the correct indicator mark? The red line or arrow should be in the middle of the numbers, not the top or bottom of the dial.
2. Did you reset the lock with three clockwise rotations before starting? If not, begin there.
3. Did your counter-clockwise turn pass the first number by a full rotation? This is the most common failure point — go back and make a deliberate full pass.
4. Are you pulling the shackle while dialing? Let it sit untouched until step four.
5. Is the combination you are using the correct one for this lock? Verify the sequence from your tag or record.

If none of these work and the lock is school-issued, contact the facility office — they have the master key or combination record. For locks you own and cannot open, Master Lock’s support page can assist with model and serial numbers.