A lock cylinder is the part of a lock that contains the mechanism operated by a key. When the correct key is inserted and turned, the cylinder allows the lock to engage or release its locking mechanism.
Lock cylinders come in many designs and are used in residential, commercial, automotive, and specialty locking systems. Depending on the type of lock, a cylinder may be removable, replaceable, or integrated into the lock hardware.
How Does a Lock Cylinder Work?
A lock cylinder works by controlling the movement of the lock's internal mechanism. In a common pin tumbler cylinder, inserting the correct key aligns the internal pins at the appropriate positions, allowing the cylinder's plug to rotate.
The rotating plug transfers movement to another part of the lock, such as a cam, tailpiece, or other locking component. This movement allows the lock to lock or unlock.
Different cylinder designs use different internal mechanisms, so not every lock cylinder operates in exactly the same way.
What Are the Main Parts of a Lock Cylinder?
The components of a lock cylinder vary by design, but a typical mechanical cylinder may include several key parts.
Cylinder Housing
The cylinder housing, also called the shell, is the outer portion that holds the internal components of the cylinder.
Plug
The plug is the portion of the cylinder that rotates when the correct key is inserted. The keyway is located within the plug.
Keyway
The keyway is the opening where the key is inserted. Its shape and profile determine which compatible key blanks can enter the cylinder.
Pins
In a pin tumbler cylinder, pins interact with the inserted key. Their positions change according to the cuts on the key.
Cam or Tailpiece
A cam or tailpiece transfers the rotational movement of the cylinder to the lock mechanism. The exact component used depends on the type of lock.
What Are the Different Types of Lock Cylinders?
Lock cylinders come in different configurations to suit different types of hardware and applications.
Mortise Cylinder
A mortise cylinder is a threaded cylinder commonly used with mortise locks and other commercial or institutional hardware. It typically screws into the lock body and uses a cam at the rear to operate the locking mechanism.
Rim Cylinder
A rim cylinder is commonly used with rim-mounted hardware, including certain rim locks and exit devices. It is mounted to the surface of the door rather than being threaded directly into the lock body in the same way as a mortise cylinder.
Key-in-Knob Cylinder
A key-in-knob cylinder is integrated into a knob or lever lock. The cylinder contains the keyway and locking mechanism within the door hardware.
These cylinders are commonly found in residential and light commercial applications.
Interchangeable Core Cylinder
An interchangeable core cylinder is designed so the core can be removed and replaced without removing the entire lock hardware. This design is commonly used in commercial environments where efficient rekeying and access management are important.
High-Security Cylinder
A high-security cylinder is designed with additional features intended to improve resistance to unauthorized key duplication, manipulation, or other forms of attack. Some use restricted keyways, specialized pins, or complex key profiles.
Tubular Lock Cylinder
A tubular lock cylinder uses a cylindrical keyway and is operated by a tubular key. These cylinders are found in specialty applications such as vending equipment, cabinets, and certain electronic or mechanical devices.
Euro Profile Cylinder
A Euro profile cylinder is a standardized cylinder shape commonly used in many European-style door locks. It is available in different configurations, including single, double, and thumbturn designs.
What Is a Lock Cylinder Used For?
A lock cylinder provides the key-operated portion of many locking systems. It allows an authorized key to control the lock while keeping the locking mechanism secured when the correct key is not present.
Lock cylinders are used in:
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Residential door locks
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Commercial door hardware
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Mortise locks
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Rim locks
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Exit devices
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Cabinets and equipment
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High-security locking systems
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Institutional locks
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Access-control hardware
The cylinder type depends on the lock and the requirements of the application.
Lock Cylinder vs. Lock: What's the Difference?
A lock cylinder is one component of a complete lock, while a lock is the complete mechanism that secures a door, cabinet, vehicle, or other access point.
For example, a door lock may include a cylinder, latch or bolt, housing, trim, and other components. The cylinder is the part that receives and recognizes the key and transfers the key's movement to the locking mechanism.
In some locking systems, the cylinder can be replaced or rekeyed without replacing the entire lock.
Can a Lock Cylinder Be Rekeyed?
Yes, many mechanical lock cylinders can be rekeyed. Rekeying changes the internal configuration of the cylinder so that an existing lock works with a different key.
This can be useful when keys are lost, access needs to be changed, or multiple locks need to operate with a new key.
The rekeying process and available options depend on the specific cylinder design.
How Do You Choose the Right Lock Cylinder?
Choosing a lock cylinder requires matching the cylinder to the existing lock hardware and its intended application.
Important considerations can include:
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Cylinder type
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Lock manufacturer
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Keyway
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Cylinder dimensions
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Cam or tailpiece configuration
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Door hardware
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Security requirements
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Key system
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Rekeying requirements
The cylinder must be physically compatible with the lock and use an appropriate keyway and key system.
Why Are Lock Cylinders Important?
The lock cylinder is a critical component of many mechanical locking systems because it controls how a key interacts with the lock. A properly matched cylinder allows authorized keys to operate the lock while maintaining the intended security of the system.
Understanding lock cylinders also makes it easier to distinguish between different types of locks, keyways, and rekeying systems used in residential, commercial, and specialty applications.
