MIT Guide to Lock Picking by Ted the Tool - HTML preview

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Chapter

9

Recognizing

and

Exploiting

P

ersonalit

y

T

raits

Real

lo

c

ks

hav

e

a

wide

range

of

mechanical

features

and

defects

that

help

and

hinder

lo

c

k

picking.

If

a

lo

c

k

do esn't

resp ond

to

scrubbing,

then

it

probably

has

one

of

the

traits

discussed

in

this

chapter.

T

o

op en

the

lo ck,

you

m

ust

diagnose

the

trait

and

apply

the

recommended

technique.

The

exercises

will

help

you

develop

the

mec

hanical

sensitivit

y

and

dexterity

necessary

to

recognize

and

exploit

the

dierent

traits.

9.1

Whic

h

W

a

y

T

o

T

urn

It

can

b e

very

frustrating

to

sp end

a

long

time

picking

a

lo ck

and

then

discov

er

that

y

ou

turned

the

plug

the

wrong

wa

y

.

If

you

turn

a

plug

the

wrong

wa

y

it

will

rotate

freely

until

it

hits

a

stop,

or

until

it

rotates

180

degrees

and

the

drivers

enter

the

keyw

a

y

(see

section

9.11).

Section

9.11

also

explains

how

to

turn

the

plug

more

than

180

degrees

if

that

is

necessary

to

fully

retract

the

b olt.

When

the

plug

is

turned

in

the

correct

direction,

y

ou

should

feel

an

extra

resistance

when

the

plug

cam

engages

the

b

olt

spring.

The

direction

to

turn

the

plug

dep ends

on

the

b olt

mec

hanism,

not

on

the

lo

c

k,

but

here

are

some

general

rules.

Cheap

padlo cks

will

op en

if

the

plug

is

turned

in

either

direction,

so

you

can

chose

the

direction

which

is

b

est

for

the

torque

wrench.

All

padlo cks

made

by

the

Master

company

can

b e

op ened

in

either

direction.

P

adlo c

ks

made

b

y

Y

ale

will

only

op en

if

the

plug

is

turned

clo ckwise.

The

double

plug

Y

ale

cylinder

lo cks

generally

op en

b

y

turning

the

b ottom

of

the

keyw

a

y

(i.e.,

the

at

edge

of

the

key)

aw

a

y

from

the

nearest

do

orframe.

Single

plug

cylinder

lo

c

ks

also

follo

w

this

rule.

See

Figure

9.1.

Lo cks

built

into

the

do

orknob

usually

op

en

clo ckwise.

Desk

and

ling

cabinet

lo cks

also

tend

to

op en

clo

c

kwise.

When

you

encoun

ter

a

new

kind

of

lo ck

mec

hanism,

try

turning

the

plug

in

b oth

direc-tions.

In

the

correct

direction,

the

plug

will

b e

stopp ed

by

the

pins,

so

the

stop

will

feel

mush

y

when

y

ou

use

heavy

torque.

In

the

wrong

direction

the

plug

will

b e

stopp ed

b

y

a

metal

tab,

so

the

stop

will

feel

solid.

27

Figure

9.1:

Direction

to

turn

plug

28

9.2

Ho

w

F

ar

to

T

urn

The

companion

question

to

which

w

a

y

to

turn

a

lo ck

is

how

far

to

turn

it.

Desk

and

ling

cabinet

lo cks

generally

op

en

with

less

than

a

quarter

turn

(90

degrees)

of

the

plug.

When

op ening

a

desk

lo

c

k

try

to

av

oid

having

the

plug

lo ck

in

the

op en

p osition.

Lo cks

built

in

to

do orknobs

also

tend

to

op en

with

less

than

a

quarter

turn.

Lo cks

whic

h

are

separate

from

the

do orknob

tend

to

require

a

half

turn

to

op en.

Deadb olt

lo ck

mechanisms

can

require

almost

a

full

turn

to

op

en.

T

urning

a

lo

c

k

more

than

180

degrees

is

a

dicult

b

ecause

the

driv

ers

enter

the

b

ottom

of

the

k

eyw

a

y

.

See

section

9.11.

9.3

Gra

vit

y

Picking

a

lo ck

that

has

the

springs

at

the

top

is

dieren

t

than

picking

one

with

the

springs

at

the

b ottom.

It

should

b e

obvious

how

to

tell

the

tw

o

apart.

The

nice

feature

of

a

lo

c

k

with

the

springs

at

the

b ottom

is

that

gravit

y

holds

the

k

ey

pins

down

once

they

set.

With

the

set

pins

out

of

the

wa

y

,

it

is

easy

to

nd

and

manipulate

the

remaining

unset

pins.

It

is

also

straight

forw

ard

to

test

for

the

slight

giv

e

of

a

correctly

set

pin.

When

the

springs

are

on

top,

gravit

y

will

pull

the

key

pins

down

after

the

driver

pin

catc

hes

at

the

sheer

line.

In

this

case,

you

can

identify

the

set

pins

b

y

noticing

that

the

key

pin

is

easy

to

lift

and

that

it

do es

not

feel

springy

.

Set

pins

also

rattle

as

you

draw

the

pick

ov

er

them

b

ecause

they

are

not

b

eing

pushed

down

by

the

driver

pin.

9.4

Pins

Not

Setting

If

you

scrub

a

lo ck

and

pins

are

not

setting

even

when

you

v

ary

the

torque,

then

some

pin

has

false

set

and

it

is

keeping

the

rest

of

the

pins

from

setting.

Consider

a

lo ck

whose

pins

prefer

to

set

from

back

to

front.

If

the

backmost

pin

false

sets

high

or

lo

w

(see

Figure

9.2),

then

the

plug

cannot

rotate

enough

to

allow

the

other

pins

to

bind.

It

is

hard

to

recognize

that

a

back

pin

has

false

set

b ecause

the

springiness

of

the

fron

t

pins

mak

es

it

hard

to

sense

the

small

give

of

a

correctly

set

back

pin.

The

main

symptom

of

this

situation

is

that

the

other

pins

will

not

set

unless

a

v

ery

large

torque

is

applied.

When

y

ou

encoun

ter

this

situation,

release

the

torque

and

start

ov

er

by

concentrating

on

the

bac

k

pins.

T

ry

a

light

torque

and

mo derate

pressure,

or

hea

vy

torque

and

heavy

pressure.

T

ry

to

feel

for

the

clic

k

that

happ ens

when

a

pin

reac

hes

the

sheer

line

and

the

plug

rotates

sligh

tly

.

The

click

will

b

e

easier

to

feel

if

y

ou

use

a

sti

torque

wrenc

h.

9.5

Elastic

Deformation

The

in

teresting

even

ts

of

lo ck

pic

king

happ en

ov

er

distances

measured

in

thousandths

of

an

inch.

Ov

er

such

short

distances,

metals

b ehav

e

like

springs.

V

ery

little

force

is

necessary

29

to

de ect

a

piece

metal

o

v

er

those

distances,

and

when

the

force

is

remo

v

ed,

the

metal

will

spring

back

to

its

original

p osition.

Deformation

can

b e

used

to

y

our

adv

an

tage

if

y

ou

w

an

t

to

force

several

pins

to

bind

at

once.

F

or

example,

picking

a

lo

c

k

with

pins

that

prefer

to

set

from

front

to

back

is

slow

b ecause

the

pins

set

one

at

a

time.

This

is

particularly

true

if

you

only

apply

pressure

as

the

pick

is

drawn

out

of

the

lo ck.

Each

pass

of

the

pick

will

only

set

the

frontmost

pin

that

is

binding.

Numerous

passes

are

required

to

set

all

the

pins.

If

the

preference

for

setting

is

not

very