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.
Generic Systems
Locks For All
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: 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 You See Here: Inspired by the scouting knives many grew up using, this refined slipjoint folding knife from The James Brand is a more elegant take on the blades of our childhood. Called The County, this particular knife measures up at 6″ in total, comes equipped with a Sandvik steel blade, and has combination stainless steel and walnut handle.
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: Complete with a high-end S35VN steel blade and carbon fiber handle scales, Zero Tolerance’s 0770CF flipper knife is like a functional piece of modern art perfect for adding to your EDC loadout. And it has a bit added bonus: it was made in the USA.
Frame Lock
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: 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 S35VN 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.
Back Lock
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: A special edition of one of the most iconic folding knives of all time, this USA-made Buck 110 Folding Hunter boasts micarta handle scales, a high-end S35VN clip point blade, and it comes with its own premium leather sheath. It also comes with Buck’s lifetime warranty, so you know you can rely on it.
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: With a unique, futuristic silhouette, CRKT’s Tighe Tac Two EDC knife features an 8Cr13MoV steel clip point blade, glass-reinforced nylon handle scales, a Tighe ball-bearing pivot system, and the brand’s limited lifetime warranty.
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: This bayonet-style automatic knife from Mikov boasts a gorgeous lilac-dyed bone handle mated to a 420 steel blade and deploys via a lightning-quick auto mechanism controlled by a simple-and-straightforward lever lock. Just make sure you can carry an automatic knife in your place of residence before trying to order one.
Proprietary Systems
Brand-Specific Locks
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.
Arc Lock
SOG
At least cosmetically, SOG’s Arc lock appears to function like a button lock. However, there are some key differences that set this one apart quite a bit. For starters, the lock is housed toward the spine of the handle in an arcing slot — hence the name — and is equipped with a one-way spring that is always engaged, putting forward pressure on the lock bar. In closed position, there is no pressure exerted on the blade. However, once you open the blade, the tang will clear the lock and allow the lock bar to slip into place in a slot on the bottom back of the tang, which prevents the blade from swinging closed — even with repeated abuse. To close the knife, the user simply has to pull back on the Arc lock and shut the blade back into the handle.
The Knife You See Here: A relatively subdued design from the tactical-heavy brand, the SOG Spec Arc boasts a 4″ high-end VG-10 steel drop point blade, glass-reinforced handle scales, and (of course) the brand’s signature Arc lock.
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. Like the Arc, this lock type is very secure. However, over time, the spring will eventually lose strength — but that’s an issue you’ll face with every knife lock type.
The Knife You See Here: An exceptional USA-made everyday carry knife, Benchmade’s Anthem boasts an ultra-thin anodized billet titanium handle with chevron-style ridges. It also comes with a CPM-20CV drop point blade, a reversible tip-up pocket clip, and it has a lifetime guarantee.
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: 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.
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 designer 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: A sturdy and ergonomic tactical folder that is minimalistic and refined enough to add to your everyday carry, the Cold Steel 4Max comes with a CPM-20CV drop point blade, titanium liners inside a 3D CNC-machined G10 handle, and a hefty pocket clip.
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: Crafted by the same family that has been making them for more than a century, this elevated take on Opinel’s signature silhouette boasts a dark oak wood handle and a black-finished Sandvik steel blade and Virobloc Safety Ring.
The Complete Guide To EDC Knife Steel
One of the most important determining factors to the quality and overall value of a knife, the blade’s material can be a daunting and confusing thing to understand. Lucky for you, we’ve simplified it in our comprehensive guide to EDC knife steel.
