This instructable will walk you through the quick and easy method for making tension wrenches from the metal inserts found in almost all windshield wiper blades.
A tension wrench is a tool used when picking a lock. If you're unfamiliar with its use, it's probably best to look elsewhere. This instructable will not show you how it's done - just how to make the tool.
Also, there is a video demonstrating this procedure in about 30 seconds at the end. If the steps aren't clear enough, that's most unfortunate, cause the video's not gonna clear it up at all (it's a whole heck of a lot darker than it was when I shot it). The download version should be a LOT better than the imbedded version.
As always - NEVER PICK A LOCK YOU DON'T HAVE A RIGHT TO!
Step 1: Pick an Insert
I have a small collection of these things, so I have the luxury to choose the height, width, and length of my tools. I use some smaller ones for smaller locks and larger ones for larger locks, as logic would have it. Most inserts fall right in the middle and can be used for either end.
Step 2: Size It Up.
Measure it if you want. I have no idea what the measurement would be. It really depends on how you like your wrenches. I tend to prefer mine on the long side as it gives me more spring. Some are shorter, to fit in tight spaces. So, it depends on the purpose of this particular wrench. Once you have a rough estimate, use the pliers to bend the insert back and forth.It should break right off.
Step 3: The Bend.
It may be surprising, but I don't measure this either. Basically,measure how much of the tool you want to be inside the lock, and insert the insert that far into the pliers and give it a 90-degree bend. I recommend making this almost exactly the same measurement as a commercially-made tension wrench if you've got one to compare it to. Otherwise, I'll give you the measurement of approximately 5/8 of an inch (I suppose I can figure out a measuring tape for that much). That size should do for most locks.
You can actually stop here, and that's how a lot of commercial wrenches are, but I like to keep going. It just depends on how you like the feel. Personally, I like to push against the flat side when I'm picking. It feels better,plus adds a bit of "spring." You'll have to try it both ways to decide.
Step 4: One Quick Twist....and It's All Over!
Using two pairs of pliers, vice grips, very very strong fingers, or whatever, give it a twist on the long side. It really is simple. Place one pair of pliers at the 90-degree bend and the other a little ways below that. An inch should be about right. Then, once you have it firmly gripped, just twist in opposite directions. You'll probably have to twist a little further than it seems you should, as the metal has a tendency to spring back a bit.
Congrats - you have a tension wrench. If you want, you can file (or Dremel) the ends to soften them up. I do recommend this, as you'll definitely cut yourself up using it otherwise.
Step 5: NEVER PICK a LOCK YOU DON'T HAVE a RIGHT TO!
DUH. NEVER PICK A LOCK YOU DON'T HAVE A RIGHT TO!