15 Common Locking Mechanisms Used For Folding Knives (An In-Depth Guide)

It’s all in the lock. A very important factor to consider when purchasing an EDC knife is the locking mechanism because it is “the heart of any folding knife”.

It ensures the blade is firmly in place, reducing the risk of damage to the knife’s structural integrity and ultimately your hand.

With so many types of locking mechanisms it may be difficult to determine which one is appropriate for you. Don’t worry, we are here to help.

Before we dive into this article, be aware that not every lock is the same and each has its pros and cons.

By the time you are done reading this article you will have a significant understanding of the different types of locking systems, how they work, and the pros and cons of each.

Ultimately the information provided will help you determine which one suits your personal needs.

In this ProSurvivalStrategies.com Guide, you will learn:

  • Why is a strong locking system important on a folding knife?
  • Why is a folding knife considered a broken knife?
  • What are the 15 common types of locking mechanisms?
  • How do they work?
  • And much more!

Why Is A Strong Locking System Important On A Folding Knife?

Folding knives are unique in their own right. These tools are portable and kept on your person either in your pocket or bag. Unlike a fixed blade knife, when folded closed, they are more compact, discrete, easier to carry and there is no exposed sharp edge. 

The lock is the “heart” of any folding knife. It ensures the blade is firmly in place, reducing the risk of damage to the knife’s structural integrity and ultimately your hand. The last thing you need is the blade being released accidentally.

However, if you are looking for a locking mechanism as strong as a fixed blade, it doesn’t exist.

Always remember, never subject a folding knife to the same type of stress as a fixed blade knife. No matter how ingenious and well-constructed its lock, a folder will always be considered a “broken knife”. 

Why Is A Folding Knife Considered A Broken Knife?

Throughout history, soldiers have relied upon fixed blades such as bayonets, daggers, dirks and swords as both primary and secondary weapons. Folding knives however were hardly seen on the battlefield and mostly suited for agrarian and routine tasks. 

Despite its humble beginnings, folders have considerably improved from materials to locking mechanisms.

Despite technological improvements, they are still considered “broken knives” because, “a folder by its very definition consists of two (and usually more) separate pieces integrated together in an attempt to make a durable and reliable whole”. 

For the significant advantage in convenience that a folder gives you for everyday carry, you give up a measure of strength.

Fixed blades on the other hand, are inherently stronger because there are no moving parts to fail under stress or after repeated hard use.

Despite the “broken knife” concept, make no mistake that folding knife manufacturers have developed amazing and secure locking systems. Today’s folding knives perform more strenuous tasks than those of our predecessors. 

What Are The 15 Most Common Locking Mechanisms Used For Folding Knives?

Some locking mechanisms are more reliable and stronger than others. As you read below you will understand why. 

LINER LOCK FOLDING KNIVES
WHAT IS A LINER LOCK?

Buck-Tops-Knife-Post-Image

Liner locks (a/k/a locking liners) have been around since the late 19th century. Michael Leon Walker (an American custom knife-maker) refined this locking mechanism by incorporating a long split in one of the liners which acts like a leaf spring within the liner to reduce mechanical stress. The ball detent eliminates rubbing and scratch marks when the knife is closed.

If you notice a metal sheet inside the handle, it’s called a liner.

Liner locks are the most common mechanism seen on folding knives because they are simple to use and easy to manufacture. 

HOW DOES A LINER LOCK OPERATE?

This locking mechanism consists of a side spring bar located on the same side as the sharp edge of the “blade lining” inside the handle. When closed, the spring bar is held under tension. When the blade is engaged, the tension slips the liner inward and makes contact with the back of the blade.

You will hear a snap which means the liner has made full contact with the back of the blade keeping it secure and preventing it from closing.

It is disengaged by using your thumb to push the liner away towards the inside of the handle or pocket clip.

Once the liner clears the back of the blade, use your index finger to push the blade down slowly. Make sure your thumb is away from the blade’s path.

Once your thumb is out of the way, close the blade completely. You will see the liner pressed firmly against the back of the blade.

Make sure you use enough force to fully engage the blade. Slow of “soft” opening doesn’t allow the lock to fully engage the tang of the blade. 

DID YOU KNOW?
The snap you hear when opening or closing a blade is called the “walk and talk”. 

WHAT ARE THE PROS AND CONS OF LINER LOCKS?

Pros:

  • They can be closed with one hand without repositioning the knife in your hand. (This takes practice).
  • They are simple to use.
  • They are found on both low and high end knives.
  • They appeal to both beginner and enthusiast knife collectors.
  • They are fast opening due to the ball detent.
  • On better quality liner lock knives, the blade pivot will fail first. 

Cons:

  • They are made from a thinner piece of metal and prone to wearing out completely.
  • They wear the side of the tang faster leading to blade play.
  • The operator’s fingers are in the path of the lade when closing.
  • They are not the most creative or exciting lock mechanisms.
  • They are prone to fine particles, sand and mud.
  • They are not ambidextrous.
  • Lesser quality knives with thin stainless steel liner locks fail when the lock itself is compressed beyond its capabilities.
  • The most frequent failure mode is the user’s failure to open the blade with enough force.
  • It might be possible to inadvertently disengage the lock while gripping the knife too tightly under stressful conditions. 

Two quick examples of knives with liner locks are the Ontario Rat II D2 and the Buck/Tops CSAR-T

FRAME LOCK FOLDING KNIVES
WHAT IS A FRAME LOCK? 

Frame-Lock-Knife-Post-Image

The frame lock, also known as the Reeves Integral Lock (RIL) named after its inventor Chris Reeves saw its debut during the 1980s. Its designer did away with the entire spring bar and instead used the entire frame/handle of one side of the folding knife to secure the blade.

It is the second most common locking mechanism used by companies around the world.

Technically you can say it’s similar to a liner lock but it’s definitely more robust. 

HOW DOES A FRAME LOCK OPERATE?

The first major feature of this locking mechanism is that a portion of the handle engages to lock the blade.

As you open the blade away from you, you will notice the left section of the handle move inwards as the blade fully opens. This section of the frame is cut to engage the bottom portion of the blade under the pivot to prevent closure.

Due to the thickness of the locking portion of the frame, the blade is securely locked into position.

To disengage the lock, you push the locking handle to the side and out of way. As tension is released, remove your thumb from the blade’s path and fold the knife closed. 

WHAT ARE THE PROS AND CONS OF FRAME LOCKS?

Pros:

  • Frame locks are stronger than liner locks because of a larger portion of metal against the blade.
  • They allow for simple construction since they have less moving parts.
  • The thickness of the locking bar provides good strength and security against accidental closures.
  • They are easily operated with one hand.
  • They have smooth opening and closing as there is no spring action on the blade. 

Cons:

  • Regular and prolonged use can wear the locking mechanism down.
  • They are not ambidextrous.
  • They rely on friction to keep the lock bar end and blade tang in place.
  • They are also prone to fine particles, sand and mud can fill the lock causing it to jam. 
  • Action is dependent on good pivot tension.

Two examples of knives with frame locks are the Zero Tolerance Emerson 0640 and Chris Reeves Sebenza 21

SLIP JOINT FOLDING KNIVES
WHAT IS A SLIP JOINT LOCK?

Swiss-Army-Knife-Post-Image

Slip joint knives have been around since the 1660s. They featured a backspring that kept the blade open. These locks are commonly found in Swiss Army Knives which have an interesting history.

During the 1880s, the Swiss Army needed a small pocket tool to open cans and disassemble their M1889 rifles which required a screwdriver. This pocket tool was manufactured in Germany and designated the Model 1890.

In 1891, the Karl Elsener company (which became Victorinox in 1921), won the contract to produce the Model 1891 for the Swiss Army and a cultural icon was born. 

WHY ISN’T A SLIP JOINT CONSIDERED A COMPLETE LOCK?

A slip joint is not “a complete lock” because minimal resistance prevents the knife from closing. This is important because in the United Kingdom, it is illegal to carry a blade over three inches and locks in place. 

UK law defines a lock knife as “ blades that can be locked and refolded by pressing a button.” Since a slip joint is not “a complete lock”, it is still a viable option as long as the blade is under 3 inches.

HOW DOES  SLIP JOINT LOCK OPERATE?

A slip joint has a metal bar spring that holds the blade opened or closed. It slips along the spine of the knife pinned to the handle in the middle of the spine.

The unpinned section near the blade applies pressure to the bottom of the blade tang, which holds the knife either opened or closed. As the blade is pulled open, the spring presses into a slot in the blade tang holding it open.

To close the blade, it requires enough force to overcome the spring tension on the blade.

Be careful because when the blade is near closed, the spring tension will close the blade the rest of the way. Keep your fingers away from the path of the blade. 

Pros:

  • Slip joints are easier to manufacture and easy on the wallet.
  • They are the most collected, gifted and traded than any other knife made.
  • They are versatile in blade configuration.
  • They can accommodate different steels, number of blades, and nearly any handle material or design.
  • They are simple and easy to use.
  • They are viable options in countries that outlaw locking mechanisms. 

Cons:

  • Slip joints do not have a true lock and are not suited for heavier tasks.
  • Since the blade is not locked the user must be careful how the knife is used to avoid injury.
  • They require two hands to open and close.
  • They become difficult to open and close over time unless you oil the pivot and clean out the dirt.
  • If the spring fails it will snap shut causing injury. 

FRICTION FOLDING KNIVES
WHAT IS A FRICTION LOCK?

Friction folding knives are the ancient grandfather of today’s locking mechanisms. They are a historical tribute to the first locking mechanisms.

Numerous bronze friction folders were discovered by archaeologists dating back to the Roman Empire. The Romas are thought to have invented the first pocket knife and yes it was a friction folder.

These tools did not have a locking mechanism. They had a simple pivot that solely relied on the handle's friction against the tang to hold the blade open. 

HOW DO FRICTION LOCKS OPERATE?

As the name suggests, these folders rely on friction to stay open or closed. The friction is created against the washer and the handle material against the blade which keeps it closed.

To engage the blade, you press down on the tab which is added to the tang which operates as a lever to open the knife. Once opened, the tab also indexes against the back of the blade of the handle where pressure from the user’s hand holds it in place stabilizing the blade during its use.

That smooth shave at the barber shop is accomplished by a friction folder. Thank god for steady hands.

Similar to the slip joint, a friction folder is not considered a complete lock. 

A VERY IMPORTANT NOTE:

Friction folders are absolutely not for novices for two reasons: 

  • They do not have locks. 
  • They require special instruction from a seasoned individual on how to operate them. (Knife safety first).

WHAT ARE THE PROS AND CONS OF FRICTION FOLDERS?

Pros:

  • Friction locks are great choices for countries that prohibit locking mechanisms such as the United Kingdom.
  • They are simple to design because they don’t have locking mechanisms.
  • They are easy to clean and maintain. 

Cons:

  • Friction folders are not used for heavy cutting tasks because of the danger of closing on your fingers. (Use your common sense).
  • You must constantly be aware that there is no lock on friction folders, a tension pivot is all that controls how easy the knife is deployed.
  • Not all friction folders have extended tangs which can lead to accidental closure.
  • Not for beginners because it takes time to learn how to use a folding knife. (seek instruction from an experienced individual).
  • They don’t all come with sheaths to prevent accidental opening. 

Two examples of Friction Folders are TOPS Knives TAC-Raze and Benchmade Aller Fumee 318

OPINEL VIROBLOC FOLDING KNIVES
WHAT IS A VIROBLOC OR SAFETY TWIST COLLAR LOCK?

The Opinel Virobloc or safety twist collar lock mechanism was developed in France by Marcel Opinel in 1955 to increase the safety and versatility of the knife by allowing the blade to be locked in the open position.

In 2000, the Virobloc mechanism was improved to allow the balde to be locked in an open or closed position.

Virobloc is the trademark name for the lock. So, if you purchase an Opinel and see the words “Virobloc Brevete” on the booster it simply means trademark patented.

A Virobloc (a/k/a a safety twist collar lock) is a very clever twisting locking mechanism located at the top of the knife’s handle which opens and closes the blade. It’s a rotating metal collar with a notch cut into it that once turned into the correct position, keeps the blade from accidentally opening or closing.

Virobloc safety rings are fitted on No.6 - No. 12 Opinel knives. 

HOW DOES THE VIROBLOC OR SAFETY TWIST LOCK OPERATE?

Operation is very simple. When the blade is vertically aligned with the slot, it is locked by twisting the ring collar located at the top of the handle. The ring collar is twisted away from the vertical slot, and the blade is locked. 

DID YOU KNOW?
In 1985 the Victoria and Albert Museum in London, England selected the Opinel Knife as part of an exhibit celebrating the “100 most beautiful products in the world right next to the Porsche 911 and Rolex Watch”. 

WHAT ARE THE PROS AND CONS OF THE OPINEL VIROBLOC OR SAFETY TWIST LOCK?

Pros:

  • Virobloc mechanisms are simple and easy to operate, a simple twist locks the blade in place.
  • Virobloc safety twist lock adds extra safety and reliability by locking the blade into a fully open or folded position.
  • The simplicity of the Virobloc locking mechanism has proved to be reliable.
  • They are cheap and easy to manufacture unlike the Axis locks found on Benchmade folding knives.
  • Takes very little pressure to close the lock.
  • Decades later this closing mechanism is still going strong. 

Cons: 

  • Opening the blade takes two hands.
  • Virobloc safety rings are only fitted on No.6-No.12 Opinel knives.
  • Not the strongest locking mechanism.
  • The rings can stiffen over time which inhibits smooth operation of the blade.
  • The ring often needs maintenance after prolonged use.
  • They can be inflexible especially when dirty or wet. 

Two examples of Virobloc locks are the Opinel Carbon No. 8 and Opinel N Degree 8

BACK LOCK FOLDING KNIVES
WHAT IS A BACK LOCK?

The back lock mechanism also known as the lock back and spine lock is commonly found on classic American folding knives. The first non-folding Buck knife was produced in 1902, by Hoyt Buck who made each knife by hand.

In 1964, the knife industry was revolutionized when the legendary Buck Model 110 Folding Hunter which featured a back lock was introduced. This made Buck Knives an iconic and undisputed American legend.

The lock back mechanism as the name suggests, is located toward the end of the spine (i.e. back) of the knife. Unlike a mid-lock located in the middle of the spine. However, both mechanisms operate the same way.

This simple mechanism features a locking blade which runs down the spine of the knife. Immediately noticeable is a space on the spine of the knife that functions like a “button”, known as a lock bar.

The lock bar is pinned in place with a pivot in the middle. A spring is anchored further towards the end of the handle which applies upward pressure behind the pivot joint which pushes the lock bar down. The lock bar must be fully compressed to open and close the knife’s blade. 

HOW DOES A BACK LOCK OPERATE?

To engage the blade, the user must use enough force to overcome the spring tension when pressing downward. When enough force is applied, the lock bar is pushed out from the tang recess and the depressing lock bar releases the lock.

Once fully opened, the front section of the lock bar comes into contact with the blade tang, locking the blade into place.

To close the blade, the lock bar is pressed downward which puts pressure on the spring which releases the lock bar from the blade tang recess. The lock is disengaged, allowing you to safely fold the blade closed. Keep your fingers away from the blade’s path. 

WHAT ARE THE PROS AND CONS OF BACK LOCKS?

Pros:

  • Back Locks are ambidextrous.
  • They are very reliable and have strong locking mechanisms since the lock bar is the same width as the blade stock itself.
  • They are definitely suited for heavy duty use.
  • The lock bar is out of the way minimizing accidental closure.
  • They are definitely stronger than liner, frame, slip joint, friction and virobloc locking mechanisms.
  • They are generally not sensitive to dirt if maintained properly.

Cons: 

  • In back locks, the most common failure is the pivot pin which secures the locking mechanism, or the tab of the lock or notched tang of the blade.
  • It might be possible to inadvertently disengage the lock while gripping the knife tightly under stressful conditions.
  • Accumulations of lint and dirt over time in the recess of the locking tang can prevent the lock from fully engaging. (Keep it clean).
  • You need both hands to close the blade safely. (Can be opened and closed with one hand with significant practice).
  • They are not the most “flickable” knives so they have a low fidget factor. 

Two Examples of Back Lock Knives are the iconic American Buck Model 110 Folding Hunter and Buck 112 Ranger

MID-LOCK FOLDING KNIVES
WHAT IS A MID-LOCK?

Buck-Midlock-Knife-Post-Image

As expected, the release lock is located in the middle of the spine and operates the same way a back lock does. However, the spine doesn’t extend all the way down to the bottom of the handle.

The reason why the lock is located in the middle is because the shorter spine can withstand more pressure which results in significant lock strength. 

HOW DOES A MID-LOCK OPERATE?

The same way a back lock does except the lock is located in the middle of the spine which is immediately noticeable. 

WHAT ARE THE PROS AND CONS OF MID LOCKS.

Pros:

  • Mid Locks are ambidextrous.
  • They are very reliable and strong locking mechanisms since the shorter spine can withstand more pressure.
  • Similar to the back lock, the lock bar is the same width as the blade stock itself.
  • They are definitely stronger than liner, frame, slip joint, friction and virobloc locking mechanisms.
  • They are generally not sensitive to dirt. 

Cons:

  • Unlike the back lock, the locking mechanism is in the middle of the handle which results in a higher probability of inadvertently disengaging the lock.
  • The most common failure is the pivot pin which secures the locking mechanism, or the tab of the lock or notched tang of the blade.
  • You need both hands to close the blade safely.
  • They are not the most “flickable” knives so they have a low fidget factor.

Two Examples of Iconic American Mid Lock Knives are the Buck 722 Spitfire and Buck 285 Bantam

TRI AD-LOCK FOLDING KNIVES
 WHAT IS A TRI AD LOCK?

Cold-Steel-Recon-!-Knife-Post-Image

Think of a Tri Ad Lock as a back or mid lock on steroids designed by Andrew Demko for Cold Steel. Cold Steel broke new ground when the Tri Ad Lock was introduced and gave the world a safe and solid locking mechanism.

The very essence of this locking mechanism is the “Stop Pin” which is the cornerstone of the locking system’s strength. It is anchored to the handles and in between the lock bar and the tang.

The pin redistributes the vertical positive and negative pressures on the lock which ultimately safeguards areas prone to being damaged. The pressure exerted when the blade is opened is transferred into the handle frame.

This system also makes a great sound when the blade is engaged.

This locking system is uniquely designed to be “self-adjusting”. As with any locking system parts begin to wear over time. However, this design adapts so the locking bar always wedges deeper into the lock channel between the stop pin and shoulder of the tang notch.

Not only is this system extremely strong, it gives the knife longevity. 

DID YOU KNOW?
Tri-Ad Locks are exclusively found on Cold Steel knives. 

HOW DOES A TRI-AD LOCK OPERATE? 

There is a space on the spine of the knife that functions like a button. When it is pressed downward, the blade is disengaged and the spine locks into a notch on the blade. A “Stop Pin”is located between the lock bar and the tang of the blade. It protects the rocker and its pivots from failing.

To close the blade, the lock bar is pressed downward which puts pressure on the spring which releases the lock bar. Once the lock is disengaged, it allows you to safely fold the blade closed.

Keep your fingers away from the blade’s path. 

WHAT ARE THE PROS AND CONS OF TRI-AD LOCKS?

Pros:

  • Tri-Ad lock patented pin redistributes pressure away from the lock and into the handle. 
  • They require little maintenance.
  • They are ambidextrous.
  • They are a strong locking mechanism, that ensures the blade is locked in place.
  • The blade is shouldered around the stop pin for increased resistance to wear and tear.
  • They are self-adjusting which significantly increases the lifespan of the locking mechanism.
  • Similar to the back and mid lock style but the “Stop Pin” redistributes pressure into the handle and away from the locking bar and blade tang.
  • Most likely the pivots will fail before the lock.
  • They are considered one of the strongest locks on the market.
  • It is a personal favorite to many enthusiasts for its solid feel. 

Cons:

  • They are not the easiest to open or close with one hand.
  • Some users complain about the amount of pressure they have to use to disengage the lock.
  • You may need to take attention away from what you are doing when opening and closing Tri Ad knives.

Two Examples of Tri Ad Lock Knives are the Cold Steel Recon 1 and Cold Steel American Lawman

BUTTON LOCK FOLDING KNIVES
WHAT IS A BUTTON LOCK?

Button-Lock-Knife-Post-Image

Button locks (also known as plunge locks) are found on automatic and manual folding knives.

The buttons on either system are basically the same. The concept behind this locking system is to provide quick access to a blade with minimum to no effort to the user.

Automatic knives clearly have a legitimate place in military and law enforcement communities. Numerous situations can arise in which the ability to deploy a blade with one hand is a lifesaver. 

For example, during World War II, paratroopers were issued the M2 and MC-1 automatic knives. The logic was due to the high probability of landing in trees or wires which had dire consequences. Either the paratrooper’ s arm was broken or caught in risers.

The autofolder gave him quick access to a blade and one-handed maneuverability in tight quarters. 

DID YOU KNOW?
In New Jersey, N.J.S.A. 2C: 39-1(p) Defines a “Switchblade”, as any knife or similar device which has a blade that opens automatically by hand pressure applied to a button, spring or other device in the handle of the knife. This is important because N.J.S.A. 2C: 39-3(e) further states that “Any person who knowingly has in his possession any gravity knife, switchblade knife, dagger, dirk, stiletto, … or … ballistic knife, without any explainable lawful purpose, is guilty of a crime in the 4th degree”. A person convicted of a 4th degree crime in New Jersey faces up to an 18 month State Prison Sentence and a fine that can reach $10,000.00. 

HOW DOES A BUTTON LOCK OPERATE?

Button lock knives utilize a spring tension button located near the pivot of the blade and handle (since coil spring automatics have constant spring pressure exerted on the blade).

When the blade is fully engaged or closed, the spring button pin locks into a recess on the blade tang. Pushing the button depresses the button pin which unlocks it from the recess tang. This allows spring tension to engage the blade immediately.

When the button is pressed, the lockup is released and allows the user to safely close the blade.

On a manual button lock system, when the button is pressed, an opening mechanism such as a flipper or thumb stud is required to deploy the blade. 

WHAT ARE THE PROS AND CONS OF BUTTON LOCKS?

Pros:

  • Button locks allow for quick deployment of the blade.
  • They are easy to use.
  • They allow one handed operation if you are injured and unable to use your other arm to engage the blade.
  • They don’t require a user to place a finger near the path of the blade.
  • They are a strong locking mechanism if the liner is made of quality steel.
  • They are ambidextrous. 

Cons:

  • Button locks stick out of the handle that an accidental opening is a real possibility.
  • They are difficult and expensive to manufacture.
  • Depending on the quality of steel used, button locks wear down on the liner portion that runs across the tang end of the blade until it goes to the liner on the other side. Then, the lock will not hold the blade securely.
  • Federal, Local and State laws regulate or prohibit ownership. (Check the law in your jurisdiction before purchasing a button lock folder). 

Two Examples of Button Lock Knives are the CRKT Tighe Tac Two and Spyderco Smock

BALISONG LOCK FOLDING KNIVES
WHAT IS AN BALISONG LOCK FOLDING KNIFE?

The Balisong is popularly known as the butterfly knife. It is also referred to as the Batangas knife after the province of Batangas in the Philippines. The locking mechanism was popularized in the Philippines during the 20th Century. However, the design itself dates back centuries.

It is unique because unlike other folders, it does not have a lock that would cause the knife to fail other than letting go. All other locking folder designs require some form of spring technology to work.

Due to the lack of a locking mechanism, the Balisong is described as a “fixed blade folding knife”. 

The very heart of the butterfly is the pivot system which enables the flipping action which made this knife famous.

The handle is split in half down the middle. Each half is attached to the blade so it can pivot. It allows the two handles of the blade to form around the blade. A latch at the end of the handles keeps the knife closed.

When closed, the handles act like a sheath to protect the blade. 

DID YOU KNOW?
In New York City there is a knife blade length restriction. It applies to blades that are 4 or more inches. New York State does not restrict blade lengths. 

HOW DOES A BALISONG LOCK OPERATE?

This system is very simple to operate. When in use, the latch at the end of the handle is opened, causing both handles to pivot backwards away from the blade tang. When the handles come together, the latch is secured. Now the blade is fully exposed.

Since both handles are gripped, “ the lock mechanism is as strong as the user’s grip”. 

WHAT ARE THE PROS AND CONS OF BALISONG LOCKS?

Pros:

  • The Balisong locking system does not rely on “spring technology” to operate.
  • They are ambidextrous.
  • The handles pivot independently allowing for unique flips and tricks. (Of course this takes time and practice).
  • The handle acts like a sheath protecting the blade.
  • They are commonly referred to as “fixed blade folding knives”.
  • They are a very simple system to operate.
  • They are easy to carry because when the balde is concealed it becomes a “small stick”.
  • The safety lock prevents the blade and handles from moving by themselves.
  • The handles are thick when connected and locked which make it easier to control the knife.
  • If you are a skilled user, it’s a great knife. 

Cons:

  • Balisongs are “extremely dangerous” for beginners. If you are not an expert using this knife, it is likely you will sustain an accidental injury. You need to undergo proper training before you handle a Balisong.
  • They are harder to handle due to the very unorthodox nature of this knife. As stated above, there are two handles and one blade which makes it complicated for new users. It is extremely tough to become comfortable with this knife.
  • It takes time to master this system.
  • Like “button locks”, Federal, Local and State laws regulate or prohibit ownership. (Check the law in your jurisdiction before purchasing a Balisong). 

Two examples of Balisong Training Knives are the Moon Boat Butterfly Trainer and Marcolo Trainer. (Sorry guys safety and training first). 

LEVER LOCK KNIVES
WHAT ARE LEVER LOCKS?

Lever-Lock-Knife-Post-Image

Lever lock knives are automatic switchblades that open with a unique flip of a lever to activate the spring for automatic action instead of a button or thumb slide.

These locks date back to over a century and commonly found on French, German, Italian and Spanish knives. For example, the history of German automatic knives began around 1850 due to the necessity of a one handed pocket knife. 

DID YOU KNOW?
15 U.S.C. 1242 - U.S. Code states as follows: Whoever knowingly introduces, or manufactures for introduction, into interstate commerce, or transports or distributes in interstate commerce, any switchblade knife, shall be fined not more than $2,000 or imprisoned not more than five years, or both. See also, 15 U.S.C. 1242 - U.S Code

HOW DOES A LEVER LOCK OPERATE?

Immediately apparent is the lock itself located at the top of the handle folded in a downward position. The lever is pulled down and depressed to engage the blade.

The main component of this system (similar to the button lock) is a tensioned pin that prevents the blade from closing. When the blade is completely engaged, the pin from the handle fits tightly into a hole located in the tang of the blade.

Once the level is depressed, it lifts the pin out of the tang allowing the blade to close.

A reverse lever lock system is more ergonomic and allows the user to slide his thumb under the lock to engage the blade. They are almost completely flush with the handle.

WHAT ARE THE PROS AND CONS OF LEVER LOCKS?

Pros:

  • They have an old world authentic Italian carmisa to them.
  • The blade is quickly deployed without any effort by the user.
  • They have a distinct snapping sound when the blade is engaged.
  • Depending on the manufacturer, some lever locks are tighter than others.
  • Some knives have reverse lever lock systems, which are more ergonomic and allow the user to slide his thumb under the lock to engage the blade.
  • They are mostly considered “collectible” or Curios. 

Cons: 

  • Lever locks can become loose and not stay in the locked position.
  • You have to reach up and pull the lever down to engage the blade.
  • They are mechanically complex which increases malfunction and a greater chance of operating parts failing.
  • They require more maintenance.
  • They can open when you don’t want them to.
  • They are not suitable for rugged outdoor use.
  • Like “Button Locks and Balisongs”, Federal, Local and State laws regulate or prohibit ownership. (Check the law in your jurisdiction before purchasing a Lever Lock Knife).
  • Remember legal issues get muddier with switchblades. 

Sorry ladies and gentleman, no examples will be posted. 

BALL BEARING LOCK KNIVES
WHAT ARE BALL BEARING LOCKS?

Ball-Bearing-Knife-Post-Image

Ball bearing locks are a unique and clever design only found on Spyderco knives. This locking system seems like a contradiction because ball bearings are designed to keep things in motion and not freeze in place.

The shape of the ball bearing itself is what gives this unique locking system some of its greatest strength. 

DID YOU KNOW?
Developed and patented by Spyderco, the ball bearing lock also known as the “caged ball lock” made its debut in 2002. 

HOW DOES A BALL BEARING LOCK OPERATE?

When the knife is closed, the ball bearing is positioned in a slightly curved channel. This channel provides the track for the ball bearing, which is pushed toward the blade due to pressure from a small shaft surrounded by a coil spring.

Opposite the curved ramp is the other side of the channel, formed by the knife’s blade. As the blade pivots, the ball bearing is pushed past the resistance of the closed closed position detent and follows a circular path until the knife approaches the open position.

When the knife is nearly open, the blade channel drops away which allows the ball bearing to push out into the channel formed at the top of the blade.

This allows the ball bearing to roll forward unobstructed with the outward spring pressure, which allows the blade to swing freely.

Once the blade is fully extended in the open position, the ball bearing locks the blade in place.

To close the blade, the user removes the outward spring pressure by pulling back on the ball bearing allowing the blade to pivot to the closed position. 

WHAT ARE THE PROS AND CONS OF BALL BEARING LOCKS?

Pros:

  • Ball bearing locks are hard to accidentally disengage, which adds to safety.
  • The hardened ball bearing rotates freely throughout its travel.
  • Since the ball bearing is in a different position, wear and tear is significantly reduced due to minimal friction.
  • Its design allows it to be operated from either side of the handle.
  • They are definitely solid and reliable locks.
  • Ambidextrous and your hand is never near the blade's edge.
  • It's one of the most elegant lock designs on the market.
  • They are easy to clean and require minimal maintenance. 

Cons:

  • The operation of ball bearing locks may feel awkward.
  • Disengaging the lock may be difficult with wet hands or gloves.
  • Sand and mud can fill the lock causing it to jam. 

Two examples of ball bearing lock knives are the Spyderco Manix 2 and Spyderco D’allara

COMPRESSION LOCK KNIVES
 WHAT ARE COMPRESSION LOCK KNIVES?

Compression-Lock-Knife-Post-Image

The Compression Lock mechanism was developed and patented by Spyderco to provide extreme lock strength and ease of use. Many refer to the compression lock as an improved inverted liner lock. However, make no mistake that this locking system is radically different and extremely stronger than a liner lock. 

DID YOU KNOW?
The compression lock first appeared on the Gunting, a knife designed by martial arts hall of famer Bram Frank. It was specifically designed for close quarter combat and defensive tactics. 

HOW DOES A COMPRESSION LOCK OPERATE?

While a user operates the compression lock like a liner lock (closing the spring tab with a side to side motion), they actually work and lock differently.

In this system, the lock actually wedges a short tab of metal between the tang on the blade and the pin that stops the blade when opening. If you try to close the knife when the blade is open and locked, the tang of the blade will actually try to compress the lock tab into the blade stop pin ("compression lock"), making it lock up even tighter.

The force is across a much shorter length of metal. 

For a compression lock to break, it would either have to shear the lock spring tab vertically and tear the stop pin out through the scales, launching it out the back/top of the knife, or blow the blade's pivot down through the bottom.

WHAT ARE THE PROS AND CONS OF A COMPRESSION LOCK?

Pros:

  • Compression locks and extremely reliable and strong.
  • The lock will hold over 200 lbs of pressure per inch of blade length.
  • The lock release nests into the web of your thumb and there is no way to inadvertently release the lock.
  • They are easy to operate with one hand and have a great “fidget” factor.
  • Ambidextrous.
  • They are all currently mounted in solid metal handles or supported by dual steel liners to increase the strength around the stop pin. 

Cons:

  • The locking bar in earlier models used to spring across upon locking, and this produced a bit of a smacking effect on the side of the index finger.
  • Requires precise tension and machining tolerances. 

Two examples of compression lock knives are Spyderco’s Paramilitary 2 and Shaman

AXIS LOCK KNIVES
 WHAT IS AN AXIS LOCK KNIFE?

Axis-Lock-Knife-Post-Image

The Axis Lock is definitely one of the strongest if not the strongest locking mechanism on the market today.

Originally introduced in 1988 by Bill McHenry and Jason Williams, the rights were subsequently purchased by Benchmade. 

Since its inception, it has inspired knife enthusiasts around the world. 

DID YOU KNOW?
The first Benchmade knife to feature the axis locking mechanism was the Model 710, which was an immediate success. It forced other knife-makers to look for similar ways to achieve similar results without infringing on the patent.

HOW DOES AN AXIS LOCK OPERATE?

The axis locking mechanism is deceptively simple. It operates by using a small, hardened spring-loaded bar that moves back and forth in a slot cut in the handles and liners near the pivot.

The spring loaded bar acts as the button and is positioned at the rear of the blade. Two Omega-style springs placed on each liner apply equal pressure, so when the blade opens the springs force the bar into a tang recess and between the sizable stop pin.

This mechanism definitely provides a solid lock up. 

There are multiple variations of this design such as:

  1. The Axis Assist, which features a spring that springs the blade into the open position once the user begins to open it manually.
  2. The Axis Automatic, which opens the blade mechanically when the Axis bar is pushed downwards.
  3. The Dual Action Automatic, which incorporates both abilities of the original Axis and Automatic Open which give the user both options. 

WHAT ARE THE PROS AND CONS OF AXIS LOCKS?

Pros:

  • Due to this unique integrated build, it allows for ambidextrous operation easily and quickly.
  • Its overall construction allows for even greater engagement with the tang as the knife is in use.
  • The pivot system can withstand over 200 lbs of force without damage, so there is no worry the locking mechanism will lead to less security.
  • Until you disengage the pin to close the blade, the blade is absolutely secure.
  • This locking mechanism is built to last because any wear that occurs only makes the tang engage more fully.
  • It is very easy to operate.
  • When releasing the lock, your fingers are not in the blades path.
  • Everyone from collectors to general enthusiast to law enforcement and military know what a Benchmade is. 

Cons:

  • Axis locks rely on two small omega springs as noted above to keep the lock engaged. These springs can break. (Keep in mind, if one breaks, the second spring will ensure the blade does not unexpectedly close).
  • They have more moving parts so these mechanisms are more expensive to manufacture.
  • They are prone to collecting dirt and debris on moving parts which is not easy to clean out. 

Two great examples of Benchmade Axis Locking knives are the Turret 980 and Bugout 535

ARC LOCK KNIVES
WHAT IS AN ARC LOCK?

SOG-Arc-Lock-Knife-Post-Image

Invented by Spencer Frazier, the Arc Lock is a locking mechanism exclusively licensed to SOG Specialty knives.

Although many state that this is a derivative of Benchmade’s Axis Lock, it differs because its cylindrical bearing is tensioned by a rotary spring rather than an axial spring. This locking system is deceptive because at first, it appears to function like a button lock. 

DID YOU KNOW?
The SOG SKS-3 was designed for and issued to the Covert Studies and Observations Group (i.e. highly classified special operations unit MAC-V-SOG) during the Vietnam War. The SKS-3 inspired Spencer Frazier and in 1986, he founded SOG Specialty Knives. 

He introduced the S1 Bowie flagship model and SOG Bowie 2.0 to honor the brave and  heroic covert warriors. 

Mac-V-Sog-Post-Image

HOW DOES AN ARC LOCK OPERATE?

The lock is positioned toward the spine of the handing in an arching slot shaped like a peanut. It is equipped with one way spring that is always engaged which exerts forward pressure on the lock bar.

The locking system is operated by the thumb which actually moves the spring loaded piston which serves as the locking bar for the blade tang.

When the blade is opened, the piston is pushed into place over the tang by a spring which secures the blade. The lock itself travels in an arc (hence the name) with a pivot point directly above the resting position of the lock in its open or closed position.

As the blade is engaged the lock bar swings out of the way, then drops into position as the blade is fully extended.

To close the blade, the user pulls back on the Arc Lock and shuts the blade. 

WHAT ARE THE PROS AND CONS OF ARC LOCKS?

Pros:

  • The Arc-Lock is very safe because it has a spring action that securely retains the blade which means your fingers are kept safely away from the blade when unlocking the knife.
  • They are durable and designed to self adjust over time.
  • They can easily be cleaned which helps with long term optimal performance.
  • They have a very good “fidget” factor and are described as lightning quick when opened.
  • They are ambidextrous. 

Cons:

  • Arc-Lock springs can break.
  • They have moving parts that are susceptible to dirt and debris. 

Two examples of SOG Arc Lock Knives are the SOG Tomcat and SOG Rescue Trident Elite

A Final Note.

Never overlook the locking mechanism when purchasing an EDC knife. The lock is “the heart of any folding knife.” It ensures blade security, structural integrity and prevents serious personal injury.

Remember, folding knives are considered “broken knives” because “ a folder by its very definition consists of two (and usually more) separate pieces integrated together in an attempt to make a durable and reliable whole.”

For the significant advantage in convenience that a folder gives you for everyday carry, you give up a measure of strength.

Never subject a folding knife to the same type of stress as a fixed blade knife “no matter how ingenious or well constructed its lock”.

So what is the best type of folding knife lock? Realistically, there is no single correct answer to this question. Different types of locks are more suited for different purposes.

Unfortunately, some locks are not well-suited for left-handed knife users such as frame and liner locks. For these users, a Back lock, Ball Bearing Lock, Compression Lock, Midlock, Opinel Lock, Tri-Ad Lock or Arc Lock are more favorable.

Some locking mechanisms inspire more confidence than others. The most important purpose of the locking system is to keep the blade where it belongs. So when a folder is the right tool for the job, it’s awesome to have a confidence-inspiring lock.

For those users in need of a hard-use blade, I highly recommend the following locks: (1) Tri-Ad Lock; (2) Compression Lock; (3) Arc Lock and (4) Axis Lock. Of course this is my personal preference.

Some locks are definitely not for novices such as the Friction Folders and Balisongs. A word to the wise, these knives require a great deal of practice to perfect their use. If you think otherwise, it’s a matter of time before you severely injure yourself.

Other locks may send you to a free stay at a State Correctional Facility. I am clearly referring to switchblades or similar devices which have a blade that opens automatically by hand pressure applied to a button, spring or other device in the handle of the knife.

The exception to this dilemma is convincing a prosecutor and judge you have a “lawful purpose” to possess the knife. Remember legal issues get muddier with switchblades or their derivatives. With so many other locks available, a trip to the can is not worth it.

Regardless of your lock preference, it’s extremely important to check your lock regularly for proper function. Make sure it is free of dirt, sand, mud and pocket debris. By allowing contaminants to build up, it can gradually cause a lock to disengage, which will lead to injury.

Even the strongest locks as mentioned above are useless if not maintained. A few seconds of your time to conduct a quick and thorough inspection is important.

Always use locks in ways that suit their intended design. Misuse can inadvertently disengage a lock. Be aware of the “death grip” when using a folding knife under strenuous conditions. For example, when applying extreme pressure to the spine of a back lock, you can accidentally release the lock.

I’ll leave you with a final thought on pocket knife locks. Never expect them to perform tasks they are not designed to do. The knife will be as useless as a fan on a motorcycle.

These knives are constantly subjected to strength tests which are interesting and impressive. However, if you are looking for a folding knife with a locking system that performs like a fixed blade, forget it. It simply doesn’t exist.

Knife safety first and always use these tools reasonably and realistically.

What’s your favorite knife lock? 

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