operating shear line n. any shear line which allows
normal operation of a cylinder or lock
original key blank n. a key blank supplied by
the lock manufacturer to fit that manufacturer's
specific product
-P-
pack n. the set of tumblers in a lever tumbler or
combination lock
padlock n. a detachable and portable lock with a
shackle which locks into its case
page master key n. the three-pin master key for
all combinations listed on a page in the standard
progression format
paracentric adj. 1. of or pertaining to a keyway with
one or more wards on each side projecting beyond the
vertical center line of the keyway to hinder picking
2. of or pertaining to a key blank made to enter such
a keyway
pattern key n. 1. an original key kept on file to
use in a key-duplicating machine when additional
keys are required 2. any key which is used in a key-
duplicating machine to create a duplicate key
personal identification number n. a series of
numbers and/or letters associated with a particular
individual as a means of identification
pick n. a tool or instrument, other than the
specifically designed key, made for the purpose of
manipulating tumblers in a lock or cylinder into the
locked or unlocked position through the keyway,
without obvious damage. v. to manipulate tumblers
in a keyed lock mechanism through the keyway,
without obvious damage, by means other than the
specifically designed key
pick key n. a type of manipulation key, cut or
modified to operate a lock or cylinder
pin v. to install pin tumblers into a cylinder and/
or cylinder plug, see also “pin tumbler”
PIN abb. personal identification number
pin chamber n. the corresponding hole drilled into
the cylinder shell and/or plug to accept the pin(s)
and spring
pin kit n. a type of keying kit for a pin tumbler
mechanism
pin stack n. all the tumblers in a given pin chamber,
see also “pin stack height”
pin stack height n. the measurement of a pin stack,
often expressed in units of the lock manufacturer’s
increment or as an actual dimension
pin tray n. see “layout tray”
pin tumbler n. usually a cylindrical shaped
tumbler. Three types are normally used: bottom pin,
master pin and top pin.
pin tweezers n. pl. a tool used in handling tumblers
and springs
pinning block n. a holding fixture which assists
in the loading of tumblers into a cylinder or
cylinder plug
pinning chart n. a numerical diagram which
indicates the sizes and order of installation of the
various pins into a cylinder. The sizes are usually
indicated by a manufacturer's reference number
which equals the quantity of increments a
tumbler represents.
plug n. the part of a cylinder which contains the
keyway, with tumbler chambers usually corresponding
to those in the cylinder shell
plug follower n. a tool used to allow removal of
the cylinder plug while retaining the top pins, springs,
and/or other components within the shell
plug holder n. a holding fixture which assists in the
loading of tumblers into a cylinder plug
plug retainer n. the cylinder component which
secures the plug in the shell
positive locking n. the condition brought about
when a key cut which is too high forces its tumbler
into the locking position. This type of locking does
not rely on gravity or spring pressure.
post (of a key) n. the portion of a bit key between
the tip and the shoulder, to which the bit(s)
is attached
practical key changes n. pl. the total number of
usable different combinations available for a specific
cylinder or lock mechanism
privacy key n. a key which operates an SKD
cylinder, see also “emergency key”
profile cylinder n. a cylinder with a usually uniform
cross section, which slides into place and usually
is held by a mounting screw. It is typically used in
mortise locks of non-U.S. manufacture.
progress v. to select possible key bittings, usually in
numerical order, from the key bitting array
progression n. a logical sequence of selecting
possible key bittings, usually in numerical order from
the key bitting array
progression column n. a listing of the key bitting
possibilities available in one bitting position as
displayed in a column of the key bitting array
progression list n. a bitting list of change keys and
master keys arranged in sequence of progression
progressive n. any bitting position which is
progressed rather than held constant
proprietary adj. of or pertaining to a keyway and
key section assigned exclusively to one end user by the
lock manufacturer. It may also be protected by law
from duplication.
-R-
radiused blade bottom n. the bottom of a key blade
which has been radiused to conform to the curvature
of the cylinder plug it is designed to enter
random master keying n. any undesirable process
used to master key which uses unrelated keys to create
a system
rap v. 1. to unlock a plug from its shell by striking
sharp blows to the spring side of the cylinder while
applying tension to the plug 2. to unlock a padlock
shackle from its case by striking sharp blows to the
sides in order to disengage the locking dogs
ratchet lock n. any lock which incorporates a ratchet
device allowing locking in more than one position
read v. to decode a lock combination visually
without disassembly of the lock or cylinder
recombinate v. to change the combination of a lock,
cylinder or key
recore v. to rekey by installing a different core
register groove n. the reference point on the key
blade from which some manufacturers index the
bitting depths
rekey v. to change the existing combination of
a cylinder or lock
removable cylinder n. a cylinder which can be
removed from a locking device by a key and/or tool
removable shackle adj. referring to a type of padlock
which is unlocked by removing the shackle from
the case
repin v. to replace pin tumblers, with or without
changing the existing combination
restricted adj. of or pertaining to a keyway and
corresponding key blank whose sale and/or
distribution is limited by the lock manufacturer in
order to reduce unauthorized key proliferation
retainer n. a component which is clipped or staked
in place to maintain the working relationship of
other components
RH abb. right hand
RHR abb. right hand reverse bevel
rim cylinder n. a cylinder typically used with surface
applied locks and attached with a back plate and
machine screws. It has a tailpiece to actuate the
lock mechanism.
Terminology
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