is stamped on the key bow. This
code can be a direct code,
which is the key’s combination,
or a blind code, which can be
utilized to determine the key’s
A direct code is essentially
what you input into code cutting
equipment to produce a key to
Direct codes correspond to bottom pin lengths belonging to the
key bitting specification (photo
1). The benefits of decoding a
key using a direct code is that it
is quick and straight for ward. A
direct code will not clue you into
the key bitting specifications,
Blind codes are very popular
for wafer locks but there are
instances of their use in other
platforms (photo 2). To derive a
key’s combination from a blind
code you must have access to
code books, code software, or
the like (photo 3). You refer-
ence blind codes against one of
these sources which in turn pro-
vides you with the direct code.
Nearly all code books and code
software contain either full or
partial key bitting specification
information; some even provide
the information to produce a key
with the combination(s) using
various code cutting equipment.
This greatly assists decoding
as well as the ability to service
additional, related keys and/or
Blind codes are often alphanu-
meric although there are times
where the blind codes can be
numbers only. These numbers
cannot be confused with direct
they will nearly
always be less
than the actual
number of cuts
found in the key.
It’s also impor-
tant to note that
you should not
confuse markings from a master
key system with blind codes.
The standard key coding system,
SKCS, must be learned, under-
stood, and practiced so that infor-
mation stamped on the key isn’t
confused with a blind code.
Keys can also be decoded
using a key gauge. Key gauges
allow you to insert a key into
cutaway portion and move the
key within the key gauge until
it comes to a stop at or near
an index marker (photo 4). At
its most basic level this index
marker will be a whole number
that corresponds with a depth/
cut within that system (photo 5).
There are key gauges capable of
decoding more than cuts in a key,
such as angles or Aft and Fore
cuts with Medeco keys, depending on the system, but that is a
story for another article. There
are also key gauges with measurements on them that function
much like a micrometer. While
not as precise as micrometer
1. A key with a direct code
stamped on it.
2. A key with a blind code
stamped on it.
3. Code books and code software assist with
decoding blind codes.
4. An assortment of key gauges
for different manufacturers and
key bitting specifications.
5. A key gauge with
incorporated into it.