When looking at purchasing locks for your home or business, the amount of options can certainly be overwhelming. There are many different types of locks and several different security factors to consider before purchasing. This page will explain the different types of locks and the security features that should be considered.
Although there are many types of locks, the four most common are padlocks, deadbolts, knob locks, and levers.



Padlocks are the only type of lock that is typically not permanently attached to anything else. Padlocks come in a range of sizes, are free standing and portable, and are one of the most easily recognizable types of lock. Padlocks come in two main varieties: combination and keyed. Combination locks have one or more number dials that open the lock when the correct combination is entered. They are often easy to decode or shim open. Keyed padlocks have several options to consider. There are rekeyable and non-rekeyable padlocks. If a padlock is non-rekeyable, then you cannot change the key that opens the lock (for example to make it use the same key as your house). Padlocks can be key-retaining or non-key-retaining. A key-retaining padlock does not allow the key to be removed while the padlock is open. Finally, padlocks can have a shrouded shackle. This is an extension of the body where the shoulders of the padlock raise up the sides of the shackle to make it far harder for bolt cutters to cut the padlock.



Deadbolts are generally installed on external doors and have a few more options to consider than padlocks. Deadbolts come in three primary varieties: single, double, and lockable thumbturn. Single cylinder deadbolts are found on most American homes. They use a key cylinder on the outside and a thumbturn (rosary) on the inside to open or close the lock. These deadbolts have one primary weakness. If access to the inside is possible (via a nearby window or even through the peephole using simple tools), the door can be opened using the thumbturn. A double cylinder deadbolt uses a key cylinder on the inside and the outside of the door to solve this issue. These have the clear disadvantage of always requiring a key to open the door from the inside if it is locked. This can pose a significant problem in a fire or other emergency situation. If used in a residential situation, it is strongly recommended that a key is left on the inside when people are present to ensure a safe exit in an emergency. The final type of deadbolt is a hybrid between a single and a double deadbolt, and is called a lockable thumbturn. It features a thumbturn on the inside that works like a normal single cylinder deadbolt, except the thumbturn can be locked using a key so it cannot lock or unlock the door. This means in a residential situation, the thumbturn can be left in an unlocked position while people are inside the house, and it will operate exactly like a standard single cylinder deadbolt. When everyone is leaving, especially for extended periods of time, the thumbturn can be easily locked so that even if someone has access to the door from the inside, the deadbolt cannot be unlocked. This type of deadbolt provides maximum flexibility and security in most situations. All deadbolts that we sell are rekeyable, however, products from some vendors are easier to rekey than others.

Knob Lock

Knob Locks

Knob locks are frequently installed in residential situations on exterior doors in addition to deadbolts, and are sometimes used as the primary source of security for doors. First and foremost, it should be said that knob locks should virtually never be used for security on external doors. The problem lies in the fact that the lock cylinder is in the knob itself and not the door. In almost all setups, they can be broken off the door with a hammer or bypassed using pliers or a wrench behind the knob, completely bypassing the locking cylinder. If you currently have knob locks, consider replacing them with simple passage knobs as it will provide almost as much security as long as you are using deadbolts on the same doors. When purchasing complete knob setups it is important to ensure the proper handedness and backset. For more details please see ourBackset/Handedness page.

Lever Lock

Lever Handle Locks

Lever handle locks are frequently used for inner doors in commercial settings. They are easier to open than knob locks as they have a large push down style handle rather than a knob that one must grasp and turn. Frequently when handicap accessibility is important lever locks are used. Our lever handle locks are ADA accessible and can be changed between left and right handedness. When purchasing it is important to measure the proper backset (see ourBackset/Handedness page ). Levers can frequently be the target of torque attacks (excessive pressure applied to the handle to try and force the lock). Some levers are “clutch” levers meaning if they are forced they just turn rather than apply pressure to the lock.

Cam Lock

Cam Locks

Cam locks are used in a variety of applications but are most frequently found in filing cabinets, mailboxes, and lower security OEM applications. They come in several different lengths and can use a variety of tailpieces or “cams” to interface with another locking mechanism. There is a very large variety of cam options, and we suggest you see our Cams/Tailpieces page. They can rotate clockwise or counter-clockwise and the amount of rotation can be limited to 90 or 180 degrees.

Mortise Lock

Rim/Mortise Locks

Rim cylinder and Mortise cylinder locks are frequently found on commercial doors, entry glass doors, and some apartment doors. While rim locks are very similar to mortise locks (many of our Abloy locks are rim/mortise combo locks) the actual hardware they are used on greatly differs. Rim cylinder locks are generally used in rim latch locks which are mounted on the inside of the door. Rim cylinder locks always have a long metal piece extending out the rear of the lock that runs through the door into a locking mechanism on the opposite side of the door. Rim locks are held in place by two screws from the inside that screw into the back of the rim cylinder. By contrast, mortise cylinder locks are threaded and actually screw into mortise hardware that is mounted within the door. They are held in place by a set screw and utilize a cam to actuate the locking hardware. Mortise cylinders come in several different lengths and there is a large variety of options for the cams depending on the exact mortise hardware they are being used in. We suggest reading our Cams/Tailpieces page for more information.

Euro Thumbturn Cylinder

Euro Profile Cylinders

Euro profile cylinders (sometimes called DIN cylinders) are frequently used in locking devices in Europe and other parts of the world. They are also used in North America in some sliding glass door locks and room dividing doors. They come in several varieties: single cylinder (one sided), double cylinder (locking cylinder on each side), and single cylinder with thumbturn (locking cylinder on one side and thumbturn on the other). The euro profile cylinder is a fairly standard form factor. The exterior (and optionally interior) lengths do vary, but the rest of the dimensions are fairly standard. Euro profile cylinders are held in place by a single screw that runs through the middle of the cylinder in most applications. Due to this single small attach point the euro profile cylinder can be easily snapped off the door if it is not of proper length or reinforced.

Key Deposit Lock

Wall Mounted Locks

Wall mounted locks are locks that are actually mounted in the wall. The most common type of wall mounted lock would be the Knox-Box or fireman’s box style lock found in many larger businesses as an emergency access to the buildings keys. Wall mounted locks can be used for more than just key storage. Some act as small safes or item deposits. Installation is generally done at time of construction although some wall mounted locks can be easily installed into existing buildings. Most wall locks can be mounted in a variety of wall surfaces. Frequently wall locks will be mounted with covers or alarm sensors to allow networking into the buildings security system (to detect unauthorized access).

Interchangeable Core Cylinder

Interchangeable Core (IC) Cylinders

Interchangeable Core Cylinders are frequently used in larger institutions and businesses and are known for their easy ability to re-key the lock by swapping out the core without taking the lock apart. I/C Locks have two types of keys that work in the lock, the standard operator key locks and unlocks the lock like normal, while the control key, when used, pulls the entire core of the lock out without removing any screws. This is very useful when upgrading locks since the door hardware can be left alone. Just the lock cores are replaced with new ones allowing the door to be upgraded in seconds. The most popular I/C Lock brands are Best, Yale, and Schlage. Their figure-eight style cores are well known and are found in many places around the world. There are different I/C lock formats with the two most popular being Small Format Interchangeable Core (SFIC) and Large Format Interchangeable Core (LFIC). It is important to note that I/C cylinders can only be installed in housings specially meant for I/C cylinders. They cannot be installed in standard deadbolts or locks not meant to take an I/C cylinder. In almost all cases if your lock can take an IC cylinder you will see the figure eight on the outside of the lock.

Furniture Lock

Furniture Locks

This category of locks actually covers a variety of locks including cabinet, desk, and sliding door locks. There are two primary styles of furniture lock, bolt style and push button style. Bolt style furniture locks have a piece of flat metal that extends out the side of the lock to secure the device. Frequently, bolt style locks are found on desks, cabinets, and drawers, although they are also used in a wide variety of other devices. Push button style locks have a rod that comes out the back of the lock that is used to secure things in place. When the lock is unlocked it pops out retracting the rod into the lock body. The device is then re-locked by pushing the lock back into its shell. A few of their common applications are filing cabinets and sliding doors. Frequently, furniture locks can be installed onto existing hardware that may not already have a lock installed.

Vending Lock

Vending/T-Handle Locks

These locks are primarily found in vending machines and T-Handle locks, although they are sometimes used in other applications. T-Handle locks are frequently exceptionally easy to replace as when you open the device you are actually pulling the t-handle lock out. Placing a new T-handle lock back in when closing the device is all that is necessary to complete the upgrade. T-Handle locks generally come in two variants, a spring latch that allows the device to be re-locked without needing a key, and a dead latch that requires a key to re-lock the device.

Jimmy Proof Deadbolt

Jimmy Proof Deadbolts

Jimmy proof deadbolts are a surface mount product frequently found on apartments and double doors. They are sometimes preferred due to the minimal door modifications required. They are also unique as the deadbolt interlocks with the jamb bracket preventing it from being simply pulled apart or forced easily from the outside. A surface mount lock means the lock screws into the inside of the door rather than having a complex drill pattern like a standard deadbolt. Jimmy proof deadbolts only require a hole drilled straight through the door for the rim cylinder. If you have an existing Jimmy proof deadbolt you can generally replace just the rim cylinder to upgrade your security. 

Complete Rim Lach Lock

Rim Latch Locks

A rim latch lock has a standard or custom rim cylinder on one side and a surface mount latch lock on the other. Rim latch locks can auto lock the door behind you and are popular in some apartment complexes. Rim latch locks are generally not meant to take a large amount of force but can be paired with other locks when used on an external door. 

Key In Knob Cylinder

Key In Knob (KIK) Cylinders

A Key in Knob cylinder is generally found at the heart of most knobs, levers, and lower cost deadbolts. They are also popular in a variety of OEM applications and even some sliding glass doors. A KIK cylinder is generally hidden inside of the lock with only the circular face of the lock being visible. Frequently, when you take the lock apart (knob/deadbolt/etc), you will find a KIK cylinder held in place with a screw. Unfortunately, while KIK cylinders all generally look similar, there are no standard specifications to their design. This can make replacing one cylinder with another of a different brand (or a high security model) challenging. Major manufacturers generally have one or more of their own designs for a KIK cylinder. Other manufacturers sometimes duplicate the style so that their cylinders can replace those produced by other manufacturers. Aside from the different sizes that KIK cylinders can have, they also have one of several different style tails on the rear of the lock. A floating tail is where the tailpiece can rotate a certain amount without the cylinder itself rotating. A fixed tail is where the tailpiece cannot rotate without the cylinder rotating. 

Abloy Boda Lock

Other Locks

There are still additional types of locks like European locks, switch locks, and deposit box locks to name a few. If you have questions about other types of locks, please contact us

Reference: https://securitysnobs.com/Types-Of-Locks.html