The 13 Type Of Knife Locking Systems, Explained

Though not everyone carries one, folding pocket knives are what we might call a commonplace item — or at least common enough that folks around the world from every walk of life are familiar with them on some level. And while you might know that these cutting tools collapse into themselves and have a blade on one end and a handle on the other, they can actually get a bit more complicated than that what with their wide array of potential materials, silhouettes, and even the mechanical bits.

If you find that you have an interest in folding knives and their constituent parts, there’s one important piece you should familiarize yourself with that might not quite as obvious as, say, the steel in the blade or the ergonomics of the handle. Of course, we’re talking about locking mechanisms. Some bladed tools have none of which to speak, others have generic systems that are fairly commonplace, and others still have brand-specific systems built-in. Whatever the case, you can learn about all of them on our complete guide to knife locking mechanisms.

Modern locking mechanisms have come an incredibly long way since the days of just slipjoints and back-locks. Today, there’re over a dozen different common locking mechanisms used on everyday carry and pocket knives. Advancements in manufacturing techniques and metallurgy coupled with new and innovative designs have given way to an ever-growing number of easy-to-use and ultra-sturdy locks that are also super affordable in many cases. There are admittedly some mechanisms that are objectively stronger than others, though the reality is that almost all modern knife locks are tremendously strong, and in very few cases will fail if being used under ordinary conditions. With that said, some locks are also easier to operate — especially with one hand. 

With strength aside, there are a few other factors and areas that should be considered when looking at knife locking mechanisms. Personal taste also no doubt plays a roll in selecting a locking mechanism. As does a mechanism’s so-called ”fidget-factor.” There are also unique variations on more common locks, as well as proprietary locks belonging to specific knife-makers — all of which we’ll be exploring in more detail below. A mechanism’s consistency and actual lockup are also of major importance, along with how easy a mechanism is to clean, service, and maintain. 

Many of the locks you’ll see on the market aren’t owned by anyone — meaning they’re generic designs free for anyone to use. That also means that these knife locking mechanisms are some of the most widely available and popular. Luckily, though they’re not proprietary, most of them still function in basically the same manner from one to the next. That being said, there are some variations (and some of those variants are, in fact, proprietary), so keep your eyes open for that where applicable.

Friction Folder

The first type of lock on our list isn’t actually a lock at all. As you might gather from their name, friction folding blades do not have any mechanism of which to speak — most often featuring little more than a blade, a pivot (the point at which the blade/handle rotates to open or close), and a very basic handle. Instead of a lock, these types of knives often have an extended tang (an extension of the blade beyond the pivot on the opposing end of the tip) that is fanned out and keeps the blade from spinning a full 360-degrees. These knives require the user to apply friction, or pressure, on the tang to keep the knife deployed in use. In the hands of the careless, this type of knife can be quite dangerous, but it’s also the oldest and most historically-significant on our list — with evidence of its application dating back to the Roman Empire or longer.

The Knife You See Here: Nagao Higonokami No. 9

Made in Japan by the descendants of the artisans who crafted katana swords for the samurai, the Nagao Higonokami boasts a reverse-tanto blade crafted from blue paper steel, a beautiful brass handle, and a lever tang. It’s also remained largely unchanged for a century and is one of the most iconic pocket knives around.

Slipjoint

Like friction folders, slipjoint knives are not technically equipped with a locking mechanism. They are, however, equipped with a mechanism that helps make them a bit more secure than their friction folding counterparts. This type of “lock,” you see, engages in two positions. First, it helps keep the knife closed, adding resistance to keep the blade in the folded position unless manually pulled past the 90-degree position. Second, it reengages when the blade of the knife is completely deployed, applying the same amount of pressure to keep the knife fully extended. This is accomplished by the addition of a “backspring” housed inside the handle itself, which can be overcome for either opening or closing with just a nominal amount of manual pressure. For reference, this type of “lock” is very common in Swiss Army Knives and the kinds of simple folding blades used by the Boy Scouts and similar outdoor-focused youth organizations.

The Knife Seen Here: The James Brand The Wayland

The James Brand’s The Wayland is a contemporary interpretation of a classically-styled Barlow knife that’s been brought to use using modern, premium materials. The non-locking slipjoint knife is crafted around stainless steel handle with a 3.0” CPM S35VN sheepfsfoot blade, and handle inlays offered in Rosewood, Sycamore, Micarta, or G10. 

Liner Lock

The first true locking mechanism on our list, liner locks are one of the most common systems you’ll see used in everyday carry knives. With liner lock knives, the handle houses a side-spring lock bar device — usually constructed from stainless steel, but can also be built from titanium — on the inside of the scales (the hollow space where the blade sits when folded) that shifts into place when the knife blade is deployed. Once in position, the liner notches against the extended blade and acts as a barrier, preventing the blade from being able to fold back down into a closed position. To close the knife, the liner must be manually shifted aside — this can be done with a finger or thumb — and the blade can once again be pushed back into the closed position. These locks are convenient and common, but they can become less secure over time, eventually requiring repair or replacement.

The Knife You See Here: CRKT Squid II

Penned by Lucas Burnley, the CRKT Squid is a compact yet thoroiguhly utilitarian EDC folder that’s modeled after sub-compact pistols. The immense success of this knife would ultimately prompt CRKT to produce batches of limited runs of top-shelf Italian-made versions of the Squid — known as the Squid II — that feature premium material upgrades in the form of a Bohler M390 blade and G10, Micarta, or forged carbon handles. Spanning less than 7.0” overall, the CRKT Squid II also features one of the most robust liner-locks we’ve ever used. 

Framelock

Think of the frame lock like the bigger, burlier brother of the liner lock. They operate on the same basic principle — a side spring (typically steel or titanium) that shifts into place beneath a deployed blade and prevents it from closing unless the spring is moved aside. The big difference, however, is that frame locks are integrated into the handles themselves, rather than added to the handle scales as a liner. That means that frame locks tend to last longer than liner locks and they’re also more reliable and stronger. Granted, they’ll still decline over time, but this happens much more gradually, requires less maintenance, and might not ever need replacing. For reference, subframe locks (which are fairly rare, even in the already small knife world) are kind of in-between separating liner and frame locks and function much the same as their kin.

The Knife You See Here: Chris Reeve Sebenza 31

Widely recognized as the grail knife in the EDC space, the Chris Reeve Sebenza 31 is the most modern take on one of the most iconic and lauded everyday carry knives ever built. This one is equipped with a S45VN or MagnaCut drop point blade, 6AL4V titanium handle scales, and a Reeve Integral Lock — which is actually a proprietary variation on a frame lock, but functions in roughly the same manner.

Backlock

Found built into many classic American-made pocket knives — like those produced by Buck and Case — back locks are probably a bit less common than liner and frame locks, but only nominally so. They also work on a very similar principle: when the knife is opened, a moving “spine” between the handle scales slips into place under the deployed blade that prevents it from folding back into the handle. The big difference, however, is that back lock mechanisms, as the name suggests, are housed in the back of the handle, rather than at the front — as is the case with liner and frame locks. Disengaging them is also a different process, as back locks have a cutout somewhere down the back of the handle that reveals a spot where users can press down on the spine, thus disengaging the lock and allowing the knife to close. Back locks tend to be very sturdy, more so than liner and frame locks, but they are also more difficult to operate, sometimes requiring two hands to close a knife.

The Knife You See Here: Buck 110

First debuting in 1964, the Buck 110 is an iconic American folding knife that features a nail nick-opening 3.75” 420 clip point blade mated to a backlock-equipped handle with ebony scales and brass bolsters and pins. Sold with an included leather sheath, the Buck 110 is also offered in a host of additional variants, including top-shelf material models and an auto version. 

Button Lock

Much more modern and even rarer than the previous locks on this list, button locks are often found on automatic knives — those that require little-to-no effort on the part of the user to deploy. In automatic knives, the lock has two functions. First, it keeps the blade from deploying when the knife is closed, plunging through the handle into a slot at the tang of the blade that prevents the deployment spring from triggering. Similarly, when the knife is open, the button notches in another slot at the base of the blade that keeps it open. This type of lock has also been used in some manual knives but has been slightly altered solely to keep the blade open and to only apply mild resistance when closed, so the knife doesn’t accidentally deploy but isn’t a chore to open, either.

The Knife You See Here: Boker Plus Kwaiken Push Button Flipper

Another iconic design from the mind of Lucas Burnley, the Boker Plus Kwaiken Push Button Flipper is a sleek and minimalistic fidget-friendly EDC flipper knife that’s constructed around a button-locking handle fitted with diagonally textured titanium scales. The handle features a flipper tab-deployed 3.03” CPM S35VN blade that offers a remarkably smooth action. 

Lever Lock

It should probably not be a surprise to hear that lever locks operate on the same basic principle as button locks, but with a couple of operational differences. First, the lever almost acts like a safety on a firearm — meaning when it’s in “locked” position, it keeps the blade from deploying. Then, when flipped, it unlocks and the user simply has to press down on it, which pulls a plunger back and allows the blade to either swing or launch open. Similarly, to close the knife again, the user simply has to push down on the lever a second time and either fold the blade back into place (or let it slide back into the handle in the case of OTF knives). This type of system is almost exclusively used in automatic knives and can be seen traditionally in stiletto type knives and originated in Italy.

The Knife You See Here: Mikov 241 Tactical Predator

The Mikov 241 Tactical Predator is an updated, modernized, tactical variant of the brand’s WW2-inspired bayonet-bladed lever-locking gravity knife. Sporting a stealthy blacked-out finish, the Czech-made 241 Tactical Predator sees a more contemporary polymer handle retain its predecessor’s level lock, while gaining a more modern dagger-style blade forged in Bohler N690. 

Although they’re nowhere near as popular or commonplace, some knife manufacturing brands have developed locking mechanisms that are exclusive to their suite of products. And that means you likely won’t see them used by any other brand (though exceptions are given to licensing agreements). That being said, just because a brand has a proprietary locking mechanism, that doesn’t necessarily mean all of their offerings are equipped with it. Again, make sure you’re paying attention and you should be able to navigate the landscape.

AXIS Lock: Benchmade

Though they are definitely different from one another — so much so that there are two separate patents filed — the AXIS lock from Benchmade operates on much the same principle as SOG’s Arc lock. It features a through-and-through design, housed in a cutout in the upper back bolster of the handle, and comes equipped with a lock bar and one-way spring that exerts pressure on a slot in the tang of the blade when opened. Similarly, to disengage the lock, the bar must be pushed/pulled backward and then the blade can flip back into closed position. Though proprietary, Benchmade’s patent on the AXIS lock reentry expired, giving way to an ever-growing host of AXIS-esque “proprietary” mechanisms from other brands. 

The Knife You See Here: Benchmade 940 Osborne

Since its debut in 2000, the Benchmade 940 Osborne has become one of the most heralded everyday carry knives in existence. Sporting a tactically-inspired design with a unique reverse tanto blade forged in CPM S30V, the 940 Osborne boasts an aerospace-grade aluminum handle with one of the Oregon City outfit’s ultra-sturdy AXIS locks. 

Compression Lock: Spyderco

The compression lock, as seen on Spyderco’s iconic PM2 folding knife, might actually be the most ingenious lock design in the entire knifemaking world. And that’s because it takes a tried-and-true concept and transforms it into one of the most secure mechanisms we’ve ever seen. You see, the compression lock is actually extremely similar to a liner lock; in fact, it operates in much the same way — the metal liner within the handle is actually a spring that shifts into place under the blade once it’s deployed, thus preventing the knife from closing without moving the spring back out of the way. However, this one is housed in the spine of the handle rather than the front. That means, along with being easy to operate and quite convenient, its also not marred by the main downside of a liner lock, as impacts and extreme usage — rather than knocking the lock out of place — serve to increase the lock’s pressure and, therefore, its security. All things considered, this is one of the most secure and reliable lock types out there right now.

The Knife You See Here: Spyderco Para Military 2

As mentioned, this is probably Spyderco’s most legendary knife design. This particular Para Military 2, which was made in the USA, comes with a grippy G10 handle and a S30V steel blade in the brand’s signature leaf shape (complete with the oversized thumb hole) that’s finished in black.

RAM-LOCK: Microtech

The RAM-LOK is a proprietary locking mechanism belonging to boutique North Carolina knife brand Microtech. The Fletcher-based firm’s state-of-the-art mechanism looks similar to Benchmade’s AXIS lock, however, looks can be deceiving, as once you start to scratch under the surface it becomes clear a lot of thought and engineering went into designing the RAM-LOK and it’s far more than just a restyled or rehashed setup. This proprietary design is constructed from one solid piece, and is a fully-caged bar lock-style mechanism that uses a closed-spring strut and an ambidextrous version of Microtech’s X Button slider on both sides of the knife. As this lock’s slider is moved back and forth — from either side of the handle — the tits spring-driven mechanism can also be seen moving up and down in the knife’s spine, smoothly guiding the RAM-LOK. The RAM-LOK is, however, like the AXIS lock in the sense that it’s super easy to use and wildly strong. 

The Knife You See Here: Microtech MSI

The Microtech MSI (short for “Microtech Standard Issue”) is a robust workhorse of an EDC folder that sports the boutique brand’s distinctive aesthetic and tactical edge. Spanning 8.90” overall, the MSI comes equipped with a 3.85-inch-long, 0.15-inch-thick modified sheepsfoot blade forged in Bohler x Microtech’s proprietary M390MK steel — an updated variation on M390.  Boasting top-shelf craftsmanship and a top-shelf fit and finish, this knife is pieced together using hardware that’s machined entirely in-house by Microtech. This knife is also offered in several different handle material options including polymer, carbon fiber, and G-10 — all of which are set on a hardened steel liner and bookending a titanium backspacer. 

Shark-Lock: Demko Knives

Andrew Demko has been designing knives and locking systems for more than three-and-a-half decades, and in that time has penned some of the sturdiest and most robust mechanisms the world has ever seen, including the Tri-Ad lock (more on that below) and the Shark-Lock. The Shark-Lock is comprised of a spring-loaded ramp — or “fin” — shaped thumb-slider that’s set in the handle just behind the base of the blade’s spine. As the blade is deployed, the mechanism’s spring-driven lock arm is pushed into notch set in the blade’s tang beneath a locking pin. Following an interesting path, the mechanism moves both up and down and fore and aft, which allows for a bigger blade tang to squeeze into the compact design, and thereby makes for a stronger and sturdier lockup. What’s more, the lock uses a drive spring that’s housed in the mechanism’s locking arm, shielding it from dust, debris, and other grime and allowing for a smoother lockup requiring less cleaning and maintenance. Not only is Demko’s Shark-Lock incredibly strong, but it’s also super fidget-friendly — not unlike button locks. 

The Knife You See Here: Flytanium Arcade

Representing the aftermarket knife specialist’s first-ever in-house folder design, the Flytanium Arcade is a modular EDC knife that consists of a type III-anodized aerospace-grade 6061 T6 aluminum handle that’s been fitted with a Shark-Lock, Ultem, Micarta, or G10 inlays, and a 3.2” CPM S35VN drop point blade. Offered in three colors and sold with two sets of included inlays, this knife was released by Flytanium alongside an enormous slew of different inlays, backspacers, and hardware sets to easily customize the Arcade — plus it’s compatible with Benchmade Bugout thumb-stud sets, furthering its customization potential. 

Tri-Ad Lock: Cold Steel

As you can probably guess by looking at it, Cold Steel’s Tri-Ad lock — which was invented by knife-maker Andrew Demko — is actually a variation on a back lock. However, it’s definitely an upgrade when it comes to strength and reliability. It still functions the same: there’s a space on the spine of a given knife that, when the blade is opened, functions as a kind of “button,” which releases the blade when compressed, allowing users to shut the knife. Inside the handle itself, the mechanism has a kind of hammer-shaped cutout that hooks into a matching cutout, like puzzle pieces, at the back of the tang of the blade alongside an additional stop pin (this is the important bit) that helps eliminate vertical blade play and makes for an altogether stronger and more secure lock.

The Knife You See Here: Cold Steel AD-10

The Cold Steel AD-10 sees the American knife brand venture into more top-shelf territory, with a CPM S35VN-steeled full-sized (8.50”) folder with a G10 handle outfitted with Demko’s insanely-strong Tri-Ad locks. Ridiculously versatile, the drop point profile and insanely durable allows this AD-10 variant to lend itself to everything from EDC to self-defense to bushcraft use. 

Virobloc Safety Ring: Opinel

Opinel’s Virobloc Safety Ring is, in short, simplified brilliance. It’s an exceedingly simple device — both in design and operation — that is as reliable and secure as it is easy to use. You see, this “ring” actually wraps around the bolster of the handle (the top section of the handle where it meets the blade) and has a small cutout where the manual blade can pass through it. Once it’s either opened or closed (yes, this is a two-way lock), the ring simply rotates manually and closes the cutout gap, thus preventing the blade from opening or closing. Granted the ring doesn’t actually lock into place — meaning it isn’t 100% secure — but it’s a simple and elegant solution to the safety issue of a non-locking knife.

The Knife You See Here: Opinel No.08

Crafted by the same family that has been making them for more than a century, the Opinel No.08 represents the French firm’s signature silhouette design. Offering stellar bang for your buck, the No.08 features a Virobloc Safety Ring-equipped wooden handle with a 3.28” XC90 carbon steel blade. And, despite measuring over 7.50” in length overall, the No.08 weighs in at just 1.6oz. 

The Complete Guide To Knife Handle Materials

Interested in further sharpening your knowledge on all things knives? Then be sure to check out our complete guide to pocket knife handle materials for a deep dive into contemporary handle and scale constructions.