warhawkhalo101 wrote:The question still remains for me: How much torque is too much?
Think of it like this - what is the minimum amount of force you need to apply to open the lock with a key?
It really isn't very much. Even though most of us probably crank the key as hard as we can every time we open a lock, the
minimum amount of force needed to actually turn the key is a lot less than we routinely use.
Now consider that a tension wrench gives you the advantage of leverage. A key gives very little leverage - your gripping point is very close to the center of rotation - and the only leverage is the width of the key handle. A tension wrench is much longer and gives you an incredible boost in leverage. This means that a much smaller force is needed to rotate the plug (albeit over a longer arc).
So what sort of resistance are we trying to overcome with the tension wrench? First, you need to overcome whatever spring force is used in the design of the lock. Some locks have a lot of resistance because the plug is attached to a tension lever or spring. If you don't apply enough force to overcome that, the plug will never turn.
Beyond that, you only need to overcome the friction between the plug and the shell and that is miniscule. Take a re-pinnable lock apart and rotate the cylinder. There is almost zero resistance. That is how much force you should apply to the tension wrench (in addition to whatever force is needed to overcome the "springiness" built into whatever lock brand you are working on).
warhawkhalo101 wrote:How gentle do I have to be with the pins so I do not overset them?
Oversetting is the result of lifting a pin too high - not on how much force you use with either your tension wrench or with your pick. Avoiding oversetting pins is a finesse issue vertically rather than a force issue horizontally (assuming single pin picking).
I bought a Master #142 tonight and was able to pick it on about my 5th try (total time less than 5 minutes). And, like almost every other lock I have picked, after I softened my approach and slowly, lightly and deliberately applied tension while really being aware of feeling the pins it opened.
You only need to be as gentle as necessary for you to truly feel what the pins are doing.
Either way, its a good starting point. I used your post LeeNo about the tension, and it has helped a lot as I keep repeating the lock to make sure I understand it, and try to find a comfortable picking technique.