by zeke79 » 20 Dec 2013 9:18
Here is a trick I use from time to time on 4 pin master #3's and similar models of master lock. I made a set of depth keys using the "laser cut" method in which there are no peaks between cuts. This leaves me with a flat across the key surface. Then I simply pick the lock open and leave the cylinder rotated then hold the lock so the key pins fall against the shell so I can see each pin length. Since 9 times out of 10 the first cut is shallow I can insert the depth keys until I cannot insert the next one in the set. I then know the cut for that specific pin and then repeat the process for all pins i can do this on. Any remaining pins I cannot do this with I make a visual comparison to a known pin next to it or use a feeler pick to compare them and estimate the cut. You can estimate the cuts within 1 cut pretty easily and then write out a progression chart.
Example, if your unknown cuts are 2413 the keys will confim the cut for the first and second pin. You can then make a visual comparison of the last pin to the second pin and use your pick to compare the second pin and fourth pin to estimate the third pin. You can then make your progression chart for cuts.
Key 1
2400
2401
2402
2403
2404
2405
2406
2407
Key 2
2410
2411
2412
2413-working key
You can simplify your chart as you get better to save time. For me the progression chart would go something like this
Key 1
2402
2403
2404
Key 2
2412
2413 - working key
This is of course much easier with a code machine.
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