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TUCoPS :: Physical Security :: locksci.txt

The science of opening locks

= The Science of Picking Locks =
=       by: Eric The Red       =
=  Tiger's Lair (206)874-4115  =

The advantages of picking or other skilled methods of entry are many: less
noise and hence less chance of discovery, no tell-tale signs that a violation
has even occurred, fewer tools are necessary than with most break and enter
methods, and lastly, but not leastly, it has more class...

With any of the picking methods presented here it is necessary to practice,
practice, practice. Any picking takes some time and lots of skill. Like most
other things in life, it is seldom accomplished as easily as presented on

A good method for effective practice is to obtain a lock that lends itself to
dismantling and remove all but two pins (one long and one short). Follow
techniques given until you have mastered the two pin lock and then try three
pins, then four, etc. Once you have this down pat, replace the two pins with
mushroom pins and start over...

Before picking any lock, squirt a bit of graphite into the locks innards to
help free it from the binding effects of dirt and other contamination.

An overview of the pin tumbler lock:
The pin tumbler lock is the most widely used lock. It offers medium to high
security and is found in doors, cars, and a host of other applications.

The principle of the pin tumbler is a series of tumblers resembling small
pins (usually 5) held in place by other pins resting on top of them, called
drivers,which are in turn, held in place by springs.

The tumblers, drivers, and springs are mounted in the shell of the lock and
the tumblers extend down in to the core of the lock. When the proper key is
inserted the tumblers are raised to this shear line, or division between them
and the driver pins. This shear line is located at the top of the core. When
this transpires, the core may be turned freely with the key.

If a key is cut too low, the driver pins will extend down into the core; too
high and the tumblers will extend up into the shell of the lock. In either
case, the core is help stationary and the lock stays locked. Pin tumblers
require a high degree of tolerace in lock and key making. About .002 of an
inch is required for correct functioning.

The most common way to obtain lock "tools" is to have a friendly locksmith
order them for you. As much as I hate to say it, many people "become"
locksmiths themselves and order the goodies on a letterhead. Some suppliers DO
check to see if they are legit, some do not.

If you choose to skip all this worry and make your own pick set simply follow
these easy to remember rules:

Get some clock spring, or even shim stock from an auto supply house. You want
the thin type, sold in strips, not the sheets.

A good range of pick thicknesses is from .025-.035"; too thin will slip the
pins out of alignment, and too think will bind in the keyway. The most useful
pick is probably the curved variety, although straight picks have their uses...

Cut the metal on a grinding wheel, dipping it in water quite often. Take care
not to burn the metal. For the curved variety you want a slight upward curve
in the end of the pick. Do not make a gradual upswing, rather a slight, sudden
upward curve directly at the end of the tool.

The other important tool is the tension tool. This is in every way as important
as the pick(s) and must fit the job or it too will bind.

Tension bars can be constructed from the same clock/spring steel. Bend the tool
into the classic "L" shape near the end. Also make several sizes and thick-
nesses of tension tools.

(about time, eh?)
Picking locks requires two intrinsic items: A pick and a tension tool. The pick
is a thin tool cut from spring steel which ends in a slight upward curve, or a
number of other tip shapes ranging from diamonds to balls and squares. The pick
is used to raise each pin to its shear line. The most popular pick is probably
the curved pick, although you should have a variety of alternatives on hand.
There are many sets on the market containing anywhere from 5 to 200 picks and
tension tools in some sort of carrying case.

The tension tool is an "L" shaped (usually double ended) piece of spring steel.
The tension tool is inserted into the core of the lock and turned slightly in
the direction that the lock opens. This tension is maintained throughout the
picking operation (a small lead weight attached the the handle of the tool may
do this job for you and free a hand to hold a flashlight, etc). As the pins are
raised to their shear line the tension you are exerting will prevent them from
falling back down into the core.

Locks that use regular, smooth pins are the easiest to pick, and are the best
to learn with. Modern Yale, Corbin, etc., are usually equipped with special
pins to make picking a more exacting operation. It is quite essential that one
learn to pick on a smooth pinned lock before attempting the challenge of an
anti-pick lock. So...try and choose a cheaper, older lock to begin with.
(Kwikset locks are quite easy.)

Place the end of your tension tool into the keyway in such a fashion that it
does not block your access to the pins. Most locks will take the tension tool
at the bottom of the keyway best; however it makes little difference to the
lock, or for that matter, to me, where you place the tool.

Exert a medium tension on the tool on the direction you suspect the lock turns.

Take your curved pick and insert it into the lock directly under the first pin.
Now, while maintaining the tension, push the pin up into the lock.

While still maintaining the tension, remove the pick. If the pin is picked the
top (or driver) pin will remain up in the lock itself, freeing the shear line.
The bottom pin may fall back down into the core, but if done correctly, the top
pin will wedge against the edge of the core (because you are turning it
slightly with the tension tool) and remain up.

Now move on to the second pin and while maintaining tension (so the first pin
will remain caught) carefully move the second pin up into the lock; of course,
you are being careful not to dislodge the first pin by a clumsy motion. You are
being careful, aren't you?


Now about this time you may discover that some of the pins slide right back
down without binding as you've come to expect from my clever instructions. You
must realize that some of the pins will be thicker than others (either on
purpose or due to uneven wear factors). This means that the thin(ner) pins will
slide back into the core while the thicker pins remain picked.

To overcome this little problem one simply picks all the thick pins first and
then goes back and attepts the thin ones. As each each pin is picked, the core
turns a bit more and as it turns the thinner pins will bind against the edge.
Soooo....go through the lock, picking all that will, and then go back and work
the more difficult buggers.

It really makes no difference if you pick from front to back or skip around,
choose the method that best matches your personality. An agent should be at
harmony with himself at all times.

As you push a pin up into the lock and it falls down, you must decide if
gravity is the cause or if the pin is being pushed by the spring. If the latter
is the case, it is, of course, not picked.

Fat pins will be harder to push up, but they will stay picked. Thin pins go up
easily and come back down easily. One may have to pick thin pins several times
before success shines its bleary eye on you.

Once you have mastered the art of picking you are ready for bigger and better
things. This next method is especially nice if you're in a hurry, or say,
you've picked up this little fox in the local singles bar and you've brought
her along on this big secret mission to impress her.

Now she has this low-cut thing on and you're a bit nervous, right? Maybe you
don't trust your hands too well, so you decide to try the rake.

Rake, I said rake. Get your mind out of the gutter.

Insert the tension tool.Now select your pick (I prefer the rake pick, but the
circle, or even curved, will suffice) and push it into the lock as far as
possible (so it is resting under ALL the pins at one time.)

Now bring the pick up until you feel it start to push up the pins, and then
draw it towards you rapidly, watching to see that it comes in contact with
every pin on the way out.

Always keep your tension on the core, and repeat this maneuver several times in
quick succesion. You may have to adjust the height of the pick as well as the
turning tension as you work. Start with a medium pressure on the tension tool,
then try light, then hard.

If the lock fails to open, then remove and try again.
In raking you are still performing the same function as in individual picking-
i.e. you are raising the pins to the shear line. Of course, you are doing it
faster than you could with each separate pin.
As you rake the tight pins will pick first and then the loose pins as the core
turns ever so little, just as in single picking. With any luck you should be
able to open the lock in 5 or 6 rakes.

This method will open many locks in a matter of seconds.

Stay tuned for more fun spy files from Eric The Red.

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