This one is a little off-brand for a site about leadership and engineering — but I keep it here because I use it. I forget my own combinations, and I hate throwing out a perfectly good lock over three numbers I can recover. This tool takes a few readings off the dial and narrows 64,000 possibilities down to a handful you can test by hand. Please only use it on locks that are yours to open.
Pull up firmly on the shackle and hold it. Slowly turn the dial and watch where it jams between two half-numbers (e.g. it locks between 4.5 and 5.5 → enter 5). Below 11 there are exactly two of these — this is the lower one.
Keep pulling up and turning past the first one. The next whole number below 11 where the dial jams between two half-numbers goes here.
Let go, then apply only light upward pressure. Turn the dial right until it stops turning freely and catches. Enter that number — if it catches on a half-number like 14.5, enter 14.5.
Enter all three readings to reveal the combinations to try.
How to take the three readings
Everything depends on tension — how hard you pull up on the shackle while turning the dial. The two sticking numbers use firm tension; the resistance point uses light tension. Work slowly and it's easy to feel.
The two sticking numbers (both between 1 and 10)
- Pull up on the shackle firmly and keep that pressure the whole time.
- Slowly rotate the dial and pay attention to where it briefly jams — it won't turn smoothly through it.
- Note whether each jam sits on a whole number or a half-number. You're looking for the jams that land squarely between two half-numbers — for example, stuck between 4.5 and 5.5 means the number is 5. Ignore any that jam right on a half-number (like 12.5).
- Below 11 there are exactly two whole-number jams. The lower one is your first sticking number, the higher one your second sticking number.
The resistance point (0–39)
- Release the shackle, then apply only light upward pressure.
- Turn the dial to the right until it stops turning freely and catches. Rock it gently back and forth to find the exact spot where it stops.
- Turn all the way around and confirm it catches at the same place two or three times. That number is your resistance point — if it catches on a half-number such as 14.5, enter 14.5 exactly.
Enter all three above and the solver lists every combination worth trying — then use the “give test” it describes to test the third number first and cut the list in half.
Based on the method popularized by Samy Kamkar for standard 40-position Master combination locks. Newer or non-standard models may not follow the same pattern.