🔓 Master Lock Combination Cracker
40-position dial · Personal lock recovery tool
Forgot your Master Lock combination? This free tool uses the last-number technique to narrow 64,000 possible combinations down to roughly 64; small enough to try by hand in about 12 minutes. Free & easy.
Step 1: Find Your Last Number
- Turn the dial clockwise 3 turns and stop on zero. This resets the lock.
- Hold the lock with the shackle pointing up. Pull down on the lock as if trying to open it.
- While holding tension, slowly rotate the dial clockwise one full turn. You find many stops, but one, and only one, will bracket a whole number like 38 between 37–39.
- For purposes of cracking the combination we will use the first number in the bracket (37 in this example) as the confirmed last digit of the combination.
- Now, the fun part. Enter your number below and try the combinations listed. It should only take about 12 minutes max.
Step 2: Enter Last Number
Enter a whole number from 0 to 39, then click Generate.
Step 3: Try These Combinations
Click a row or the ✓ button to mark it tried. Click again to unmark.
| # | 1st | 2nd | Last |
|---|
| # | 1st | 2nd | Last |
|---|
Frequently Asked Questions
How does the last-number technique work?
A 40-position Master Lock's internal mechanism creates one unique stopping points when you apply tension and rotate the dial. Those stops are clues to determining the last number. When a whole number is bracketted by two other whole numbers that's the last number. We use the lower number in the bracket for our calculations.Knowing the last number reduces the total possible combinations from 64,000 to around 64, which can be tried in about 12 minutes.
How many combinations does a 40-position Master Lock have?
A standard 40-position Master Lock has 64,000 possible three-number combinations (40 × 40 × 40). Once you know the last number, valid first and second number combinations drop to approximately 64 due to the lock's internal mechanical constraints.
How long does it take to try all the combinations?
Most people finish in 10–15 minutes. Each combination takes about 10–15 seconds: reset (3 clockwise turns), 1st number (clockwise, pass it twice, stop on the third), 2nd number (counter-clockwise, pass it once, stop on the second), 3rd number (clockwise directly to it, pull shackle).
Does this work on all Master Lock models?
This tool works for standard 40-position combination dial locks made by Master Lock, including the popular #1, #3, and similar models with a 0–39 numbered dial. It does not apply to word-combination locks, padlocks with fewer positions, or electronic locks.
Is it legal to crack my own Master Lock?
Yes! Using this technique on a lock you own is entirely legal and is the same method locksmiths use for personal lock recovery. It is illegal to use this method on any lock you do not own or without the owner's explicit permission.