Disclaimer:
This post provides information dealing with how to defeat a specific lock. It is up to the reader to decide how this information will be used. No one but the reader is responsible for any actions taken with this information. This is for educational purposes only.

Earlier this evening, I was going through some boxes still in the attic from our move a couple years ago. While looking for a book, I came across a master no. 646 padlock: http://www.masterlock.com/cgi-bin/produ ... late=style
Now, I had no idea as to what the combination was, so I looked it up in the 'ol LSS. This specific lock was not in the book, but a similar one was. According to the author, this lock can be defeated with a lock scope, which I don't own. I rotated the dials and noticed you can see these cuts in the wheels quite easily, without any aid.


The cuts are barely visible in this photo, but looking at this lock in your hand, it is a lot clearer. By the way, these cuts are only visible when the lock is upside down, and you want the largest of the cuts, there are smaller ones that are visible as well. Now, I lined up these three digits in the are where you usually enter the combination.


By adding seven to this result, you will arrive at the proper combination:


Have fun

Also - I discovered while playing with my Brinks sesame-style padlock that you can derive the combination through manipulation. I'll describe the process as follows:

1.) Hold the lock on the palm of your left hand with the shackle on the left side so that your thumb can "pull up" on it and maintain the pressure.

2.) While looking at the four digits rotate the wheel on the far right, you will notice there will be an increase in resistance against turning this wheel followed be a sudden release. If done right the sudden release will stop on the correct number.

3.) Perform the same process on the second wheel from the right and so one until the last of the four wheels is in place.

NOTE 1: As you set the correct number for each wheel, they will become increasingly difficult to decode. I ussually set the 3 wheels on the far right so that I have only 10 combinations to try - which pretty much takes 10 seconds.

NOTE 2: There will also be a resistance to turning the wheel as the wheel aproaches "0". You'll learn to tell the difference with practice.

OMG, those 646's are so much easier to open than that dude. Stuff notches and scopes, just pull on shackle, turn wheels until they give, and its open. I can open these in like 5 seconds flat, and have done it to numorous different locks of the same model.

hmm, I tried what you mentioned before posting with no luck, perhaps I just didn't try long enough