On 2011-01-23, Ignoramus3188 wrote:
On 2011-01-23, rangerssuck wrote:
I thought now would be a good time to relate a story about locks.
[ ... ]
really be that easy, can it? So, I bought a cheap set of lock picks,
and took a whack at it. It really was THAT easy.
[ ... ]
A long time ago, a locksmith told me, "Locks are to keep honest people
honest. If a bad guy wants to get in, he's going to get in." After my
brief experience with picking various locks, I believe him.
[ ... ]
Rangers, do you think that there are better locks, costing, say, $100,
that are not so easy to pick?
There are things which can be done to a standard pin-tumbler
lock to make it more difficult to pick -- but certainly not impossible.
The most common thing is "mushroom tumblers" (or "spool tumblers"),
which look sort of like this (use a fixed pitch to view -- yes, Iggy, I
know that you will anyway, but this is for others).
+--+ +-
| | | \
| +-----------+ |
| |
| |
| +-----------+ |
| | | /
+--+ +-
This is used instead of a plain cylinder. It can replace both the driver
(the part just below the spring) and the part which the key actually
lifts, with varying degrees of curvature on the right-hand end (as
drawn). The driver would be closer to flat, while the part which
contacts the key would be more rounded.
The idea being that when the tension is applied, you wind up
with the split between the plug and the body shifting into the turned
down section, and trapping the pin so you can't get the actual point of
join lifted to the right height. (Of course, this is weaker, and if
someone drives a screwdriver blade into the lock and twists hard, it may
well shear all the pins at the thin point -- especially if *all* the
pins are of this type instead of being full cylinders.
The Medeco brand locks have a somewhat more complex design, and
are both pick resistant, and require a very special tool to duplicate
the keys. (Instead of the grooves all being at right angles to the key
blank, they are alternately tilted down to the right or left.)
The Ace barrel locks (the kind found on vending machines) are
quite difficult to pick as well, especially if fitted with mushroom
tumblers -- but I don't think that you can find them in a format to
mount in a door.
But -- before going into all of this -- consider how strong
everything around the lock is. For example, if there are glass panes
beside the door, it is easy to break the glass and reach through to
unlock from the inside.
Or the typical door these days is a hollow core with a honeycomb
of cardboard separating two thin wood strips, so it is fairly easy to
break through that, too.
For the glass beside the door situation -- consider a knuckle
lock with cylinders on both sides of the door -- so you need a key to
lock or unlock it from inside as well as outside. Then, if they break
the window, there is still nothing for them to turn.
But remember -- all of this will only slow down a sufficiently
determined attacker.
And yes, I have picked door locks for co-workers who locked
themselves out. I typically would make the tools for the use from old
bandsaw blades, accomplish the rescue, and then destroy the tools, just
so I am not found walking around with a lock pick set. :-)
Enjoy,
DoN.
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