question regarding theory behind SFIC fingered torque tool

[inverseentropy]

I think I have a pretty good understanding of how the Best SFIC lock works... but I'm having a hard time understanding (or believing in) the fingered torque tool as described on Matt Blaze's site. The idea, as far as I can tell, is to generate torque on the control shear line but not the operating shear line.

Now, a shear line is the line between two concentric cylinders so torque "at" a shear line is really relative torque between two cylinders. In the case of the control line the torque is between the outer and middle cylinders, and in the case of the operating line, between the middle and inner. The torque tool in question has little fingers that reach into the little holes on the bottom of the lock and grab the middle cylinder, supposedly applying torque only to the control line. The problem, in my mind, is that when rotational force is applied to the tool the other side of it necessarily presses against the keyway. Assume that the wrench is being turned clockwise (ie. the handle extends to the right and is being pushed downwards). The bottom of the tool pushes leftward on the middle cylinder, and the top of the tool pushes rightward on the inner cylinder (and below the axis of rotation). So, the outer cylinder is stationary, the middle cylinder is torqued in the clockwise direction, and the inner cylinder is torqued in the anti-clockwise direction. The end result is that there is a shear force on both shear lines. Right? The forces on the two shear lines may not be of the same magnitude though... There are a lot of things going on here but I think the shear on the operating line would be stronger than that on the control line, which is opposite of what is desired.

It is possible to apply force on only the middle cylinder if the tool is pulled to the right instead of being torqued, but I don't think it would stay in place very well and this is probably not how it is typically used. Apparently people get this tool to work but I have a conceptual problem with this theory. I have a cut-away lock and some normals, none of which are pickable by me with my homemade finger wrench, although my materials and workmanship leave much to be desired (street sweeper blade and Dremel cutoff wheel). OK, I think I was able to pick the cutaway by looking at the pins, but no more easily than with a standard tension wrench. Again, other people have had success with this tool so it obviously works... but how?

[LocksmithArmy]

your problem in understanding lies here

The torque tool in question has little fingers that reach into the little holes on the bottom of the lock and grab the middle cylinder, supposedly applying torque only to the control line.

it does not apply pressure to only one, it applies pressure to both, meaning that the inner and middle cylinders that would creates a shear line now move together as one... making no shear line... only the outer cylinder has a shear line now...

hope that helps

[inverseentropy]

OK. It would have to be a very tight fit in order for the inner and middle cylinders to move as one without any torque between them. This would explain why the shims are needed.

[thelockpickkid]

Shims? I have seen these tools in action and they work. I have a tension wrench that bins on the bottom and will do the same thing just not as good. I have a youtube video of me opening a Falcon like this. Just look up thelockpickkid.

[LocksmithArmy]

well petersons likely dont need shims, they are made to fit correctly, the one talked about in matt blazes article is the same idea but requires shims to fit multiple ic profiles... if I am not mistaken

[ridinplugspinnaz]

For what it's worth, I own the Peterson SFIC tension tools, and I haven't had an ounce of luck with them, personally. I'd love to see a proper video of someone using them correctly to pick a control shear line, start to finish. Any takers?

[keysman]

For what it's worth, I own the Peterson SFIC tension tools, and I haven't had an ounce of luck with them, personally. I'd love to see a proper video of someone using them correctly to pick a control shear line, start to finish. Any takers?

I used the " IC Wrench" 1x many years ago.. no luck , but a nice idea.

I have about equal luck picking to the control line as the opening line. No particular method.. just luck I guess. if it opens to theopening line I just start again.

[inverseentropy]

With my cutaway lock, pin #1 tends to be the first (or maybe second) pin to bind on both the control and operating lines. It passes the control line first and then the operating line, but I am not able to feel it passing the control line. If I lift it exactly far enough to satisfy the control line, I can generally pick the rest of the lock to control position since the operating shear line remains forever bound on pin #1. It is rare that I can do this without looking at the pins though, and I have never successfully opened the non-cutaway locks (although they could probably use some oil).

I imagine that this sort of thing is typical for these locks. Opening them obviously happens more often than with the probability of 1 in 2^N suggested on Blaze's page.

[unlisted]

Even with the proper tension tool, there is a known "fix" to that tool exploit, and it may of been implemented on all the locks you tested it out on.

[CaptHook]

Correct, the pin holes on the control sleeve are often elongated with a file or dremel tool. This takes away the ability to use the icore wrenches.
However there is another option. Get a hold of some flat brazing rod and make yourself some thick wrenches. You can sand/file them to whatever thickness you want. You can make a wrench that will wedge between the warding of the plug and the control sleeve so that both will turn at the same time.
Chuck

[pjzstones]

i've made a couple of these wrenchs and they work really well on one of my 6 pin sfic best padlocks and the others it doesn't seem to even make a difference. wish it did though cause i've been trying to pick one of them to the control line for at least 3 months now.

[ElAbogado]

Even with the proper tension tool, there is a known "fix" to that tool exploit, and it may of been implemented on all the locks you tested it out on.

Yes there is a fix, or modification, that eliminates the holes in the bottom of the keyway and the possibility that a torque tool could be applied to that particular cylinder. Also the Arrow SFIC and the Sargent (new type) SFIC do not allow the shell to wrap around the cylinder and reach the bottom of the lock, thus eliminating the efficacy of this special tool.

El Abogado

[thelockpickkid]

I am not sure but I believe that Ken Peterson actually has some youtube videos showing the use of his products, these SFIC tools may be one of the subjects, I seem to remember him demonstrating them somwhere.

[WOT]

Even with the proper tension tool, there is a known "fix" to that tool exploit, and it may of been implemented on all the locks you tested it out on.

Yes there is a fix, or modification, that eliminates the holes in the bottom of the keyway and the possibility that a torque tool could be applied to that particular cylinder. Also the Arrow SFIC and the Sargent (new type) SFIC do not allow the shell to wrap around the cylinder and reach the bottom of the lock, thus eliminating the efficacy of this special tool.

El Abogado

If the holes are plugged, the core can not be serviced anymore.

[ElAbogado]

Even with the proper tension tool, there is a known "fix" to that tool exploit, and it may of been implemented on all the locks you tested it out on.

Yes there is a fix, or modification, that eliminates the holes in the bottom of the keyway and the possibility that a torque tool could be applied to that particular cylinder. Also the Arrow SFIC and the Sargent (new type) SFIC do not allow the shell to wrap around the cylinder and reach the bottom of the lock, thus eliminating the efficacy of this special tool.

El Abogado

If the holes are plugged, the core can not be serviced anymore.

the holes are not plugged, they are enlongated with a dremel tool and an abrasive cutoff wheel to eliminate the ability of the tool to grab the sleeve and apply the torque to the sleeve/control line. The cylinder is completely serviceable after modification.

See Matt Blaze's article here: http://www.crypto.com/photos/misc/sfic/

El Abogado