Interchangeable core
Encyclopedia
An interchangeable core or ic is a compact keying mechanism in a specific "small format" figure-eight shape. Unlike a standard key cylinder, which is accessible for combinating only via locking device
disassembly, an interchangeable mechanism relies upon a specialized "control" key
for insertion and extraction of the essential (or "core") combinating components.
, mortise lock
, padlock
and so forth) and then installed into another without requiring the removal or disassembly of any single component. These units are readily adapted for master keying systems and can be set up with spare cores and keys for quick replacement when security is compromised, such as when a key is lost or stolen or when a personnel change takes place. Extracted cores can then be recombinated without urgency and placed back into maintenance storage for future use.
Although operationally similar to removable cores, which come in varying "large format" snowman shapes, interchangeable cores neither dictate nor exclude the use of a particular hardware manufacturer. In other words, whereas a typical large format key system of Brand X must be expanded with Brand X cores and must use Brand X cylindrical locks and cylinder housings, a typical small format key system of Brand A can be expanded with cores from Brands A, B, C, D, E and so on, and can also be used with locks and housings from Brands A, B, C, D, E and so on.
with the combinating pins in the chambers of the mechanism; as a consequence, these keys are always configured and cut from blade tip to bow
. Conversely, conventional cylinders and removable cores utilize a shoulder near the bow of each key to properly align all peaks and valleys; as a consequence, these keys are always configured and cut from bow to blade tip. As a further consequence of this fundamental difference, neither of these two key types can ever be cross- or master-keyed with the other.
As a benefit to keying from blade tip to bow, a six- or seven-pin interchangeable core key blank can be machined to precisely fit a smaller five-pin system configuration. Although the blade of such keys may be a pin or two longer than need be, this extra length never enters the locking mechanism; therefore, five-, six- and seven-pin interchangeable core systems can be easily integrated to work with one another or to provide different levels of access control within the same system. Conventional cylinder and removable core systems are significantly more limited in this regard since the extra length of their keys must pass through to the inside of the locking mechanism, which is often just not physically possible.
For additional interchangeable core access control, non-proprietary keyway
s and key sections of the following designations are available: A, B, C, D, DD, E, F, G, H, J, K, L, M, N, Q, R, TB, TD and TE. Other less common but still non-proprietary keyways and key sections also exist, but these typically have differing designations from manufacturer to manufacturer, even though the components may otherwise be identical.
standard for keying interoperability throughout the commercial door hardware industry. Product offerings are no longer limited just to the two originally competing companies - Best Universal Lock and Falcon Lock - and can be optionally specified from all OEM
and most aftermarket door hardware brands in North America:
The modern interchangeable core - and all other cores, as well - actually has its roots in a bulkier, pedestal-shaped removable configuration developed in 1919 by Frank Best, then proprietor of Best Universal Lock Company. Frank Best's family business lineage has since expanded over the years but, currently, is most recognizable via the two competing Indianapolis, Indiana area entities generally referenced with his surname: Best Access (Stanley Security Solutions, Inc dba
Best Access Systems
) and Best Security (Marshall Best Security Corp).
, BiLock, Corbin-Russwin, Medeco, Mul-T-Lock, Sargent, Schlage and Yale
are not interchangeable with any other make or model. Although similar in appearance when installed, no two actually share exactly the same form or function. More precisely, for example:
Lock (device)
A lock is a mechanical or electronic fastening device that is released by a physical object or secret information , or combination of more than one of these....
disassembly, an interchangeable mechanism relies upon a specialized "control" key
Key (lock)
A key is an instrument that is used to operate a lock. A typical key consists of two parts: the blade, which slides into the keyway of the lock and distinguishes between different keys, and the bow, which is left protruding so that torque can be applied by the user. The blade is usually intended to...
for insertion and extraction of the essential (or "core") combinating components.
Functionality
Interchangeable cores can be extracted from one lock type (bored cylindrical lockBored cylindrical lock
A bored cylindrical lock is one in which two holes are bored, perpendicular to one another, into the door. A large hole is bored into the door face and a smaller crossbore hole is bored into the door edge, as opposed to a mortise lock prep cut into the edge of the door...
, mortise lock
Mortise lock
A mortise lock is one that requires a pocket—the mortise—to be cut into the door or piece of furniture into which the lock is to be fitted...
, padlock
Padlock
Padlocks are portable locks used to protect against theft, vandalism, sabotage, unauthorized use, and harm. They are designed to protect against some degree of forced and surreptitious entry.- History :...
and so forth) and then installed into another without requiring the removal or disassembly of any single component. These units are readily adapted for master keying systems and can be set up with spare cores and keys for quick replacement when security is compromised, such as when a key is lost or stolen or when a personnel change takes place. Extracted cores can then be recombinated without urgency and placed back into maintenance storage for future use.
Although operationally similar to removable cores, which come in varying "large format" snowman shapes, interchangeable cores neither dictate nor exclude the use of a particular hardware manufacturer. In other words, whereas a typical large format key system of Brand X must be expanded with Brand X cores and must use Brand X cylindrical locks and cylinder housings, a typical small format key system of Brand A can be expanded with cores from Brands A, B, C, D, E and so on, and can also be used with locks and housings from Brands A, B, C, D, E and so on.
Key Attributes
Interchangeable cores require a notch at the tip of each key to properly align the peaks and valleys of each bladeKey (lock)
A key is an instrument that is used to operate a lock. A typical key consists of two parts: the blade, which slides into the keyway of the lock and distinguishes between different keys, and the bow, which is left protruding so that torque can be applied by the user. The blade is usually intended to...
with the combinating pins in the chambers of the mechanism; as a consequence, these keys are always configured and cut from blade tip to bow
Key (lock)
A key is an instrument that is used to operate a lock. A typical key consists of two parts: the blade, which slides into the keyway of the lock and distinguishes between different keys, and the bow, which is left protruding so that torque can be applied by the user. The blade is usually intended to...
. Conversely, conventional cylinders and removable cores utilize a shoulder near the bow of each key to properly align all peaks and valleys; as a consequence, these keys are always configured and cut from bow to blade tip. As a further consequence of this fundamental difference, neither of these two key types can ever be cross- or master-keyed with the other.
As a benefit to keying from blade tip to bow, a six- or seven-pin interchangeable core key blank can be machined to precisely fit a smaller five-pin system configuration. Although the blade of such keys may be a pin or two longer than need be, this extra length never enters the locking mechanism; therefore, five-, six- and seven-pin interchangeable core systems can be easily integrated to work with one another or to provide different levels of access control within the same system. Conventional cylinder and removable core systems are significantly more limited in this regard since the extra length of their keys must pass through to the inside of the locking mechanism, which is often just not physically possible.
For additional interchangeable core access control, non-proprietary keyway
Keyway
A keyway is the shaped channel in a lock cylinder into which the key slides to gain access to the lock tumblers. Lock keyway shapes vary widely with lock manufacturer, and many manufacturers have a number of unique profiles requiring a specifically milled key blank to engage the lock's...
s and key sections of the following designations are available: A, B, C, D, DD, E, F, G, H, J, K, L, M, N, Q, R, TB, TD and TE. Other less common but still non-proprietary keyways and key sections also exist, but these typically have differing designations from manufacturer to manufacturer, even though the components may otherwise be identical.
Brief Background
Since hitting the market in the middle nineteen sixties, and in spite of its atypical keying configuration and limited availability, the interchangeable core has gradually evolved into a de factoDe facto
De facto is a Latin expression that means "concerning fact." In law, it often means "in practice but not necessarily ordained by law" or "in practice or actuality, but not officially established." It is commonly used in contrast to de jure when referring to matters of law, governance, or...
standard for keying interoperability throughout the commercial door hardware industry. Product offerings are no longer limited just to the two originally competing companies - Best Universal Lock and Falcon Lock - and can be optionally specified from all OEM
Original Equipment Manufacturer
An original equipment manufacturer, or OEM, manufactures products or components that are purchased by a company and retailed under that purchasing company's brand name. OEM refers to the company that originally manufactured the product. When referring to automotive parts, OEM designates a...
and most aftermarket door hardware brands in North America:
- Abus, Alarm Lock, American, Arrow, Best Access, Best Security, BlueWave, Cal-Royal, Corbin-Russwin, CX-5, Dorma, Falcon, GMS, General Lock, Hager, IEI, Ilco, Independence2, InstaKey, K2, KabaKaba GroupKaba Holding AG is a global security group based in Rümlang, Switzerland, and employing around 8,000 staff in over 60 countries. They are a publicly-traded company listed on the SIX Swiss Exchange.- History :...
, Killeen, Lori, LSDA, Marks, Master, Medeco, Mul-T-Lock, Olympus, Omnilock, Onity, PDQ, Precision, Saflok, Sargent, Schlage, SDC, Tell, Trans-Atlantic, Von Duprin and YaleYale (company)Yale is a lock manufacturer owned by Assa Abloy. It is associated with the pin tumbler lock, which is often known as the Yale lock.- History :...
either produce their own interchangeable cores or else offer product lines or product options to accommodate such cores by others.
The modern interchangeable core - and all other cores, as well - actually has its roots in a bulkier, pedestal-shaped removable configuration developed in 1919 by Frank Best, then proprietor of Best Universal Lock Company. Frank Best's family business lineage has since expanded over the years but, currently, is most recognizable via the two competing Indianapolis, Indiana area entities generally referenced with his surname: Best Access (Stanley Security Solutions, Inc dba
Doing business as
The phrase "doing business as" is a legal term used in the United States, meaning that the trade name, or fictitious business name, under which the business or operation is conducted and presented to the world is not the legal name of the legal person who actually own it and are responsible for it...
Best Access Systems
Best Lock Corporation
Best Lock Corporation is the former name of a publicly traded door hardware and lock manufacturer. Originally founded in 1925 as Best Universal Lock Company by Frank Ellison Best, the privately held company relocated from Seattle, Washington to Indianapolis, Indiana in 1938, where operations...
) and Best Security (Marshall Best Security Corp).
Disambiguation
Large format removable cores from manufacturers Assa AbloyAssa Abloy
The Assa Abloy Group is a Swedish lock manufacturer, the world's largest by sales. Assa Abloy was formed in 1994 when ASSA AB was detached from Swedish security firm Securitas AB. Shortly thereafter the Finnish high-security lock manufacturer Abloy Oy was acquired. The company was introduced to...
, BiLock, Corbin-Russwin, Medeco, Mul-T-Lock, Sargent, Schlage and Yale
Yale (company)
Yale is a lock manufacturer owned by Assa Abloy. It is associated with the pin tumbler lock, which is often known as the Yale lock.- History :...
are not interchangeable with any other make or model. Although similar in appearance when installed, no two actually share exactly the same form or function. More precisely, for example:
- Each core from Corbin-Russwin is removed and reinstalled via a partial two-chambered pin section with a unique shear line that rotates into and out of the chassis when any common change key or master key with the proper cuts is encountered, and, therefore, is incompatible with all Schlage removable cores, which release and resecure by means of a lateral pin at the back that is controlled by a specialized key cut to match any functioning change key or master key or combination thereof.