by dboeren » 10 Jan 2008 23:27
A tension wrench is just something to provide a turning force, something the key would normally be doing if you had one. It's usually a thin 'L' shaped piece of metal, nothing special. It doesn't do any of the picking itself, but by using it to apply a very light tension you create the conditions for the other tool (the lockpick) to do its job of lifting the pins one by one and hopefully opening the lock.
I don't know what sort of lock is in a SENTRY safe, so I'm not sure how hard it will be to pick. There are some people who are seriously very good at lockpicking and make it look easy. They may be able to open difficult locks in a short amount of time that a beginner couldn't open in several hours of trying.
Basically if it has a normal looking key it probably has between 4-6 pins. It's possible that one or more of those pins are security pins, which means that instead of being plain brass cylinders they are specially shaped to fool someone that is trying to pick the lock. The most common security pin shapes look like a letter 'I' or have a mushroom top. If it does have security pins, it will be a much harder lock to pick.
To be totally honest with you, it's unlikely that you'll be able to open it unless it's a very poor lock. If you're serious about the attempt, I would advise buying a cheap deadbolt to learn on first. For about $12 or so pick up a Kwikset deadbolt at Home Depot, open it up, and take out 4 of the 5 pins. Learn to pick it with only one pin in place, then add a second, and so on. In this way you will build your skills until you can open it with all five pins. Then scramble the order of the pins and do it some more. Once you're comfortable with that you can try to tackle the SENTRY lock, but that's no guarantee you'll be able to get it, especially if it does have security pins.
As far as tools, if you use something improvised it will be harder than with a proper pick. You can basically make a pick out of a paperclip and a pair of pliers to bend the end up a bit. A tension wrench can be a doubled over paperclip. It has to be wide enough to apply a turning force in the keyway without slipping.
If you're handy with tools you can download lockpick templates and make them yourself with a dremel or bench grinder. Common raw material are cheap hacksaw blades, windshield wiper inserts, or metal street sweeper bristles.
Hope this helps, but it's also quite likely that your best bet is going to be breaking it open (hacksaw, axe, hammer, etc...) or going to a locksmith.