deadlocking adj. pertaining to any feature which,
when fully engaged, resists attempts to move the
latch or bolt in the unlocking direction through
direct pressure
declining step key n. a key whose outs are
progressively deeper from bow to tip
decode v. to determine a key combination by
physical measurement of a key and/or cylinder parts
decoder gauge n. a measuring device which helps
determine the combination of a lock or cylinder
without removing the tumblers
depth key set n. a set of keys used to make a code
original key on a key duplicating machine to a lock
manufacturer's given set of key bitting specifications.
Each key is cut with the correct spacing to one
depth only in all bitting positions, with one key for
each depth.
derived series n. a series of blind codes and
bittings which are directly related to those of another
bitting list
direct code n. a designation assigned to a particular
key which includes the actual combination of the key
disc tumbler n. 1. a flat tumbler which must be
drawn into the cylinder plug by the proper key so
that none of its extremities extends into the shell
2. a flat, usually rectangular tumbler with a gate
which must be aligned with a sidebar by the
proper key
double-acting lever tumbler n. one that must
be lifted a precise amount, neither too little nor too
much to allow movement of a bolt
double bitted key n. a key bitted on two opposite
surfaces
double pin v. to place more than one master pin in
a single pin chamber
drilled key n. a type of bit key with a hole drilled
into the shank from the tip
driver spring n. a spring placed on top of the pin
stack to exert pressure on the pin tumblers
drop n. a pivoting or swinging dust cover,
see also “increment”
dummy cylinder n. a non-functional facsimile of
a rim or mortise cylinder used for appearance only,
usually to conceal a cylinder hole
duplicate v. to copy, see also “duplicate key”
duplicate key n. any key reproduced from a
pattern key
dustproof cylinder n. a cylinder designed to prevent
foreign matter from entering either end of the keyway
-E-
effective plug diameter n. the dimension obtained
by adding the root depth of a key cut to the length
of its corresponding bottom pin which establishes
a perfect shear line. This will not necessarily be the
same as the actual plug diameter.
ejector hole n. a hole found on the bottom of
certain interchangeable cores under each pin chamber.
It provides a path for the ejector pin.
ejector pin n. a tool used to drive all the elements
of a pin chamber out of certain interchangeable cores
electrified lockset n. a lock which is
controlled electrically
end ward n. a ward which prevents complete
insertion and/or rotation of an incorrect key by
forming an obstruction to the end of the key
end ward cut n. any cut made into a key to bypass
an end ward
-F-
factory original key n. the out key furnished by the
lock manufacturer for a lock or cylinder
fail-safe adj. a feature of a security device designed
to release, for safety purposes, during a power loss
fence n. 1. a projection on a lock bolt which
prevents movement of the bolt unless it can enter
gates of properly aligned tumblers, see also “sidebar”
2. any locking element other than a sidebar or
shackle designed to enter a tumbler's gate
file cabinet lock n. 1. any lock used on a file
cabinet 2. a plunger lock cylinder for a gang lock
normally used in a file cabinet
finish n. a material, coloring and/or texturing
specification
first generation duplicate n. a key which was
duplicated using a factory original key or a code
original key as a pattern
first key n. any key produced without the use of
a pattern key
five column progression n. a process wherein key
bittings are obtained by using the cut possibilities in
five columns of the key bitting array
five pin master key n. a master key for all
combinations obtained by progressing five
bitting positions
flat type key n. a key which is completely flat
on both sides, usually used for warded or lever
tumbler locks
flexible head mortise cylinder n. an adjustable
mortise cylinder which can be extended against spring
pressure to a slightly longer length
foot n. the cam portion of the trunnion assembly in
some lever tumbler locks
four column progression n. a process wherein key
bittings are obtained by using the cut possibilities in
four columns of the key bitting array
four pin master key n. a master key for all
combinations obtained by progressing four
bitting positions
frangible shackle n. a padlock shackle designed
to be broken easily
frangible shackle padlock n. a padlock equipped
with an easily broken shackle
-G-
gate n. a notch cut into the edge of a tumbler
to accept a fence or sidebar
GGGMK abb. great great grand master key
GGGMK'D abb. great great grand master keyed
GGM abb. great grand master key
GGMK abb. great grand master key
GGMK'D abb. great grand master keyed
GM abb. grand master key
GMK'D abb. grand master keyed
graduated drivers n. a set of top pins of different
lengths. Usage is based on the height of the rest of the
pin stack, in order to achieve a uniform pin stack
height. See also “compensate drivers”
grand master key n. the key which operates two
or more separate groups of locks, which are each
operated by a different master key
grand master key system n. a master key system
which has exactly three levels of keying
grand master keyed adj. of or pertaining to a lock or
cylinder which is or is to be keyed into a grand master
key system
great grand master key n. the key which operates
two or more separate groups of locks which are each
operated by a different grand master key
great grand master key system n. a master key
system which has exactly four levels of keying
great grand master keyed adj. of or pertaining to a
lock or cylinder which is or is to be keyed into a great
grand master key system
great great grand master key n. the key which
operates two or more separate groups of locks which
are each operated by different great grand master keys
Terminology
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