What is the strongest locking mechanism for a folder?

Strongest: Clearly the Tri-ad by cold steel is extremely strong, as is the Axis-lock, Arc-lock and reinforced liner lock (AutoLAWKS). There are many others that are probably less strong, like ring-lock, slip-joint, mid-lock, clasp-lock, and basic liner lock (and similar frame lock), lock-back (and stronger mid-lock).

But which of all these, or others if you can find a better system is truly the 'strongest' of all folding knives?


References:
http://www.knife-depot.com/blog/a-guide-to-the-types-of-knife-locking-systems/
http://www.bladeforums.com/forums/showthread.php/781977-Axis-vs-tri-ad
http://www.everydaycommentary.com/2011/11/lock-types.html

That's a good question but the only way to know for sure which lock is the strongest would be to torture test all the different locks from all the different knife companies out there until each lock fails and I don't even know if anyone has ever done anything like that.
Cold Steel does do tests like that on their own knives and some of them are pretty impressive...


http://www.youtube.com/watch?v=OQbmb5CRJzU

I feel most comfortable with a frame lock as exemplified by Chris Reeve's Sebenza and similar designs. Next step would be a small fixed blade.

I've always been a fan of the triad and axis locks from benchmade and sog's arc-loc. They're all incredibly strong(I've used them for absurd cutting chores most would leave to fixed blades), but the axis locks are my favorite due to the ergonomics. They allow me to single-handedly flick open and close the knife in a flash..all while keeping myself out of the path of the sharp side(unlike the triad and liner-locks).

The arc-lock found on sog's spec elite, pentagon elite, visionary, and vulcan is superb. It's smoother than the benchmade lock due to it having an eggish cam-shape that swings over to lock behind the blade rather than a round bar that slides over like on the benchmades. On the benchmade axis lock(like on my bone collector axis with d2), I can feel a scraping grit as it opens that just isn't there on the sog...even though the engagement surfaces are near mirror smooth. I also like that on either design, there is a progressive engagement angle of the axis lock that self-adjusts for wear. If the lock pin or the blade wear, the lock just engages a little more into the locking surface rather than loosen up(the triad does this too).

I like how damned solid and strong the lockup is on the triad lock, but dislike how much material is taken off the back of the blade to allow for the rather large locking surface. I also dislike that it's not very one-hand friendly(which can be a issue on the spartan...more than once i've almost guillotined my finger inside the grip where the blade acts almost like a cigar-cutter). You definately need to take attention away from what you're doing to make sure you're safely opening and closing the triad knives...you don't need to with my spec elite or benchmades(this is also a reason i don't like assisted opening knives...they're not any faster and they make one-handed closing difficult if not unsafe)

Liner locks are a tricky thing. While i'd prefer my vantage pro had a benchmade or sog style axis-lock, the liner lock on it is done well and very solid. On knives where the liner engagement surfaces are cut correctly and fitted properly(they should not be parallel surfaces, but diverge slightly with a gap towards the back of the knife for best strength), the liner locks are very strong. My issue is both that you have to put your hand in the path of the blade as you unlock it(talked about above) and that if you're realllly digging the tip of a knife into something, the meat of your hand can accidentally move the liner and unlock the knife.

On the vantage pro, the carson flipper also acts as a nice choil and stops the blade from accidentally closing on your fingers. If I have a liner-locked knife, I always look first for some form of choil to stop the blade from closing on me should i carelessly mess up. The one reallly, realllllly solid liner lock i have is my crkt m16-01t. It's solid because of the secondary locking mechanism that moves down to lock behind the liner to keep the liner from disengaging. Once the blade its out, it's as good as a fixed blade with that secondary lock.

http://www.bladeforums.com/forums/sh...eformance-Test

blade forums is a nice place to visit to read from industry professionals and get the word from the horses mouth on the why's of design and materials for any given knife. I read for hours there and still feel completely green in the knife world. It's hard to wrap my mind around the metallurgy. There's so much to heat treating, martensite, austenite, alloys, and internal stress of metal in combination of different manufacturing processes that i just feel overwhelmed when reading. It's very much part science and part art to produce good steel at an optimum hardness(and often times steel has an optimum hardness...if different properties are needed, a different alloy at it's optimum hardness should be used instead of underhardening or overhardening the alloy).

Balisong .

Nuff said .....

JohnnyBmore said:

Balisong .

Nuff said .....

Click to expand...

....show off

Any new folding knife locks since I posted this last year?

Everyone still feel the strongest is Cold Steel's Triad lock?

Has to be an automatic feature that actuates when one quickly opens the knife, not an additional step, i.e. something you have to do after it's open, like twisting a locking screw, or pushing up on a locking bar, etc.

I saw something briefly on a new-ish Spyderco knife, it was like a reverse lock; compression lock... and any opinions?

Long but my opinion if anyone cares…

The AXIS lock is strong, but has one major weakness. If the omega springs break, the knife is essentially useless. Generally one will usually break before both go, but both breaking in short succession is not unheard of. It can be affected by the elements to the point of difficult function and disabling via a detail strip is very complex. The frequency of this is really debated…it’s not common, but also not unheard of. Most (practically all) users will not be able to put the pieces back together as there are many small pieces which are a PITA to work with. There is also no way to do a minor field strip while being able to adequately service the lock (Benchmade will service it for essentially free, but you have to mail it)…plus disassembly voids the warranty. Still it is a great lock and one of the many innovations from a great company. I don’t think quite as much of the Arc Lock.

Liner locks can be extremely strong, but when exposed to elements (and sometimes shock), the lock can fail. Sand between the liner and lockbar can prevent the tight lockup that liners need and can cause a light 'spine whack' (or any back pressure for that matter) to disengage the lock.

The Tri-Ad is one of and probably the strongest lock made depending how you evaluate. I’m not a Cold Steel fan but it has more to do with their integrity…them and Microtech have a habit of stealing the works of others. Nonetheless, Cold Steel makes some great weapons and they’ve made some excellent in-house productions.

Spyderco’s spine lock first used on the Chinook I and then the (first gen) Manix is one of their strongest locks. The build on that type of lock is heavily overbuilt. They’ve been using lockbacks for so long that they’ve really become the masters. Things such as adding the David Boye Detent with smoothed edges and SS liners makes the knives even more capable (and suited for self-defense). They make some of the finest spine locks in the business…and they pair them with blades with some of the best geometry in the business as well…and at a competitive price at that. Their compression lock, first seen on the Paramilitary and a few less popular models, offers excellent strength, ease of usage, and the integrity of the lock is virtually unaffected by the elements. I’ve never understood why it has not caught on more as it’s a huge breakthrough IMO and offers something a little different but equally capable.

I personally look for a knife that has a lock with very particular characteristics. First and above all, it must be simple. Simple to use, simple to detail strip, and simple to repair/replace parts. One of the requirements I have is capability for the user to service and capability to detail strip without voiding the warranty…that reduces selection by a good 90% plus. The strongest most fail-proof locks in the world will eventually fail if they cannot be serviced and I don’t like having to mail a knife away to do this or risk voiding the warranty if I do it myself. Sand, grime, clay, dirt, oil, adhesives, solvents, even dust and other common elements can cause locks to fail…so in addition to physical force strength, I look for a lock that does not lose its integrity when it is caked up with crud. I also want a lock with longevity. Most (almost all) knives will develop at least a small amount of vertical and lateral blade play over months or years of usage…five years, ten years, and twenty years after I buy the knife, I want the lockup so tight that even if I use all the force I can that there is zero lateral or vertical blade play whatsoever. So in addition to withstanding abuse, I look for the ability to withstand abuse without any changes to factor tolerances such as no blade play and the blade sitting perfectly centered in the handle when closed. I want a lock that utilizes PB washers (preferably perforated ones to retain grease) instead of ones made of plastic along with a reinforced pivot joint in which the joint is thicker than a simple thin screw/rivet.

The lock which is easiest to service is without a doubt the Reeve Integral Lock (AKA ‘framelock’ or ‘monolock’ although they are slightly different but with the same general concept). The knives are usually around only 10 pieces and can be completely detailed stripped, cleaned, and reassembled faster than a chain smoker can burn a cigarette. Every part is an easy replacement. They also are not affected by elements nearly as much as other locks, especially in regards to tolerances. Zero Tolerance, Strider, and Chris Reeve make almost all of their flagship knives using this type of lock only…generally the lockbar is hardened/quenched titanium using a detent to prevent accidental opening. Wear is very slow even after decades of usage. Spyderco, Benchmade, and others also make fine examples of this lock type. CRK and ZT have introduced washer systems designed to keep heavy weight grease inside of the pivot while keeping other elements out…making a dry system, which can go for years without needing cleaning and still function smoothly. For those looking for a knife that will be used in areas where there is tons of crud to cake up inside pivots, this is one of the biggest advancements in years IMO. ZT’s recent jump in pivot design is quite possibly their single most important contribution to folding knives, and they have contributed many. The strength of these folders is plenty strong enough for virtually anything one will need. Something like the ZT0301, CRK Umnumzaan, or Strider SMF is a serious folder that can withstand throwing, batoning, chiseling, whittling, back-cutting, cutting other steels, and more. In addition to strong locks, the blades are generally a little softer to make field sharpening easier and give the blade greater impact resistance if the user must use the blade in a fashion as if it were a fixed blade. Harder blades (of the same steel) can sometimes become more prone to catastrophic failure when exposed to shock.

My personal opinion is that the Reeve Integral Lock/framelock is the finest lock. CRKs usage of it for years is a major reason why the Sebenza has become the yardstick in which virtually every folding knife is compared to. ZT’s advancement are pushing this lock type even further. A few ZT designers posted an article years back on why they chose the Reeve Integral Lock for all of their high-end folders over other evaluated lock types. Strength was one of the biggest factors, but there were numerous others. ZTs design details are very interesting, especially given they have had TONS of knives they have made, evaluated, and not bring to market because they do not meet their standards of making a knife that can be abused…this includes a failed OTF automatic and numerous side-opening autos in which the lock strength was the primary reason they were scrapped. The last decade has seen the Blade’s Knife of the Year award dominated by knives using these locks and I believe that their robustness, strength, and longevity are largely why, and deservingly so at that.

As far as what has changed from last year, ZT has made some major advancements on lock technology and many of their new items have won some of the highest awards in the industry. http://www.knife-depot.com/blog/zero-tolerance-unveils-new-knives-at-shot-show/

Excellent write up, thanks.

In conrast to proclivities in so many other regards, I am suprising cynical about folding knives.

1. Long ago I realized that I lost far more knives than I ever broke, and also more than loosened to point of unserviceability.

2. A knife w/o play at the blade is called a full tang fixed blade. If somthing pivots, it has tolerences.

3. Edge geometry is somthing I create myself to my inclinations. And don't expect to find on a purchased knife.

4. I like steel a step ahead of the ubitiquous no-name chinese crap. But I learned to free hand sharpen at a formative age , and don't mind the ocasional touchup. Heck patina lends character , so I'd be cool with 1095 , if it were still used in mass market folders.

4. Folding knives are disposable. I don't sink enough capital into one to be disturbed when it gets lossed or tossed. I prefer to get older ones from flea markets and yard sales. Ones that were made in USA with medium decent steel , but ugly enough the sellers don't think it's a valuable collectable.

If it weren't for the Penknife Exemption , I would have a US mfg Sharpfinger perminantly on my belt.

Framelock.

No question.

Awesome posts Smokey and Nickzac

There is far more to a lock than strength, especially if it is measured simply as the force required to break it clamping the blade edge down in a vise, and hanging weight from the handle. In this type of test the Demco Triad and Axis locks are probably king, although even decent liner locks like Emersons would probably take more force than anyone realistically would apply. Then there are spinewhack "tests" that some swear by, and most laugh at. I guess it would kinda mirror "what is the strongest handgun", might end up being a HI point that mostly sucks in every other way compared to most other pistols, there is a lot more to a lock than strength. In a quality knife, the lock will likely be strong enough, but there are a ton of other factors, jimping, comfort, blade shape, jimping, weight, ease of lock use, deployment, clip design, and jimping that will probably be more important in use. There may be the option of a fixed blade, and almost without exception a full tang fixed blade is stronger than any folder, but they have limitations too, in MD it is the law, sometimes it is the need for a sheath instead of clipping it in your pocket or the length of a sheathed knife that make a folder work better for you than a fixed blade.

In most cases of failure, the lock came loose, it didn't break, this is pretty much where liner locks criticism comes from, most of their failures are from the liner slipping off the blade, especially with shock, or from inadvertently disengaging them being your finger usually contacts the lock during use. They can be poorly fit or wear and cause play, or in some designs the lock can slide past the blade aggaint the far scale and unlock. They do require your fingers to be over the channel as the blade is unlocked, but that is a minor gripe IMO, they can get jammed with dirt, and a grain of sand in the wrong place can cause under-engagement. The design requires liners which can increase strength at some expense to weight, but probably their best attribute is that they are easy to use, done well with thick liners and good material they can be sufficient. The spyderco PM2 compression lock at first appears to be a "backwards" liner lock, springing over, locking and unlocking on the spine side of the handle instead of the blade side. It is a different animal entirely, the small tab of the liner snaps over and wedges between the blade tang and a pin, force and shock keep it in place instead of forcing it open, and being the detent on the lock tap can be pushed away, the blade can be flopped open or closed without resistance.

Framelocks are one of the more prevalent lock designs in higher end folders, and an honest improvement over liner locks. The lock face can generally be larger and thicker, there is no scale over the lock to trap dirt, it's as easy to use as a liner, and while your finger contacts the lock, it generally pulls it tighter with use instead of pushing it unlocked, although some may sacrifice a bit of comfort as it makes the finger area narrower. Some improvements like Hinderer's lock stop button can help prevent damage by over extending the lock past it's unlocked position, really the only gripe some have with this lock. While it may not be as "Strong" as some designs, the simplicity, ease of cleaning, ease of use, and sufficient strength keep it as a good popular option.

Back locks are one of the older lock designs, and can still be good strong ambidextrous locks. They can place the lock tab away from where it can be inadvertently unlocked, and some modifications like the Boye dent make them even less likely to be inadvertently disengaged. Their strength is in direct proportion to the depth of the cutout and lock pivot pin, deeper cutout, stronger lock/weaker blade, so there is a limit. In some midblock designs like spyderco uses they can be ambidextrous one handed locks. The main issue is that downward blade pressure is also applied to the lock, and it's pivot pin, OK for light EDC, but bad for a hard use folder, Demco built the Triad lock with a pin in between the lock and blade to take this stress, and it is probably the strongest lock in big folders as a result. The issue there is that it makes the pivot area large to be sufficiently strong, increasing the overall length for a given blade size and can make it awkward to open. The lock can be slow to work, and the spring on some cold steel designs is stiff, but is almost immune from inadvertent unlocking.

The Axis lock has been Benchmade's bread and butter for years, and for good reason. It's incredibly strong, easy to use, ambidextrous, and allows some unique opening and closing methods as it acts as the detent for the blade, and can release the blade to swing freely open or closed. The limitations is that it requires liners unlike back lock or framelock designs, and the failure prone Omega springs, and while the BM300 is proof a flipper can be done with an axis lock, it is very difficult and pretty much the only design with one. Arc locks are similar, but instead of a pin moving in a channel it swings in on short arms ancored to a second pin, takes up a bit more room though. There are some tooth lock knives where a pin or plate slides in and out, but unlike the Arc and axis, they are not ancored across the liners, and are not as strong. A number of autos and a few manual folders use piston locks, a round spring loaded plunger that locks in a detent on the blade tang, they hold up to vibration, but don't have the depth of engagement or strength of an Axis lock. Spyderco has the Bearing lock on the Manix2, and it's another design, instead of a pin bridging across liners, a caged ball bearing is wedged in between a steel backspacer and the blade tang, it uses a coil spring instead of an omega spring, and the bearing is free to roll smoothly as the blade opens or closes, no need for liners, and can do all the opening and closing tricks an axis can do. While the locking surface area of a ball is smaller than a pin, the backspacer is solidly pinned and screwed into place as it supports both the spine stop and lock taking both up and down forces on the blade.

alucard, you are the undisputed king of tl; dr.

I will have to read this stuff when I have more time. I have a SOG Flash-II, not sure what lock mechanism it has but I like it. I removed the safety lock, and this knife has never self-deployed in my pocket. I close it with one hand constantly, using my thigh or something to move the blade back into the handle.



Si vis pacem para bellum

follow me @DiscipleofJMB

smores said:

alucard, you are the undisputed king of tl; dr.

I will have to read this stuff when I have more time. I have a SOG Flash-II, not sure what lock mechanism it has but I like it. I removed the safety lock, and this knife has never self-deployed in my pocket. I close it with one hand constantly, using my thigh or something to move the blade back into the handle.



Si vis pacem para bellum

follow me @DiscipleofJMB

Click to expand...

I don't know, a couple folks are catching up

It's a kind of toothlock same as the trident they call a "piston lock", although what most call a piston lock(including me in my last post) is a round button that slides in from the side into a matching cutout on the blade different usually found on autos. On the SOG lock the bar slides in under spring pressure to wedge between the tang and backspacer, there is a secondary lever lock in the back to prevent unlocking. The older version and Flash 1 have a direct linkage, a simple plastic button to slide it in or out, the Trident and newer flash 2 have an arc lock looking hinged actuator button to lever against the bar. It is acompletely different design from the arc lock, not ambidextrous, way more complex, and not as strong. Being it relies on the plastic backspacer on one side to wedge the lock in place, with a small screw as the only metal reinforcement they can and do flex or break the plastic and the lock fails. I guess they just didn't want to adapt AO with an arc lock

Biggfoot44 said:

2. A knife w/o play at the blade is called a full tang fixed blade. If somthing pivots, it has tolerences.

Click to expand...

Frame locks are very good at avoiding blade play...and amusingly enough, liner locks are one of the worst for avoiding blade play. A Sebenza wont have blade play that a human can physically detect, unless perhaps using a microscope to evaluate blade play at an amplified level. The way the knife is designed, the lock essentially avoids play developing through the oversized pivots and a lockbar designed to naturally lock tightly and apply retaining pressure from all directions to avoid play. You can take it apart and put it back together hundreds of times, or replace parts from other lot numbers, and you still won't have blade play. It's a niche market knife and very, very expensive, but it's tolerances are in the thousands of inches. My customs and William Henrys aren't even that consistent. And there are great frame locks for a lot less, such as the Spyderco Sage. Spyderco and Benchmade (among others) both make folders using the same lock type as used on the Sebenza and they also have very tight tolerances and a lock designed to remain in spec after tons and tons of usage...which can easily be measured in decades on a folder with a good quality frame lock.

alucard0822 said:

Awesome posts Smokey and Nickzac

There is far more to a lock than strength, especially if it is measured simply as the force required to break it clamping the blade edge down in a vise, and hanging weight from the handle. In this type of test the Demco Triad and Axis locks are probably king, although even decent liner locks like Emersons would probably take more force than anyone realistically would apply. Then there are spinewhack "tests" that some swear by, and most laugh at. I guess it would kinda mirror "what is the strongest handgun", might end up being a HI point that mostly sucks in every other way compared to most other pistols, there is a lot more to a lock than strength. In a quality knife, the lock will likely be strong enough, but there are a ton of other factors, jimping, comfort, blade shape, jimping, weight, ease of lock use, deployment, clip design, and jimping that will probably be more important in use. There may be the option of a fixed blade, and almost without exception a full tang fixed blade is stronger than any folder, but they have limitations too, in MD it is the law, sometimes it is the need for a sheath instead of clipping it in your pocket or the length of a sheathed knife that make a folder work better for you than a fixed blade.

Click to expand...

I see you are a bit of a knife freak as well.

You're spot on. I’ve always found spine whack tests to be not very important, but with a few possible exceptions, such as any folder designed to be used in self defense using a back cut in which the upswept tip is inverted and used to tear skin/move limbs. While a spine whack will not test all of this, I think it is a component although better for testing impact/shock resistance (for both the lock and blade) than outright strength. A lock failure mid-back cut with a 4inch razor sharp blade would be...yucky. Certain utility work in which excessive force is applied on the lock may also count. Some people seem to have set ritual(s) to examine the knife’s overall integrity, much like a function check is done with a firearm before shooting, which makes sense to me. The function check I do on my folders isn't very extensive at all, but if were to carry a knife possibly used in a fashion that will stress the lock, I'd probably step it up a little.

And I wish Benchmade would do something about the issue with the omega springs…while relatively rare, it’s arguably the biggest single con of the AXIS lock. With Benchmade’s ingenuity, I would expect them to develop something to change or add additional redundancy/early diagnoses before catastrophic failure. With everything they have done and give to the industry, that seems like child’s play to them. I’d also like to see them make a knife using an AXIS in which the knife can be partly (and easily) disassembled for cleaning the areas that are hard to reach without some disassembly without a good ultrasonic cleaner (plus a warranty that is not voided if field stripped). Being able to detail strip my CRKs completely down to removing every individual component, clean and lube the parts, and then put back together in under 2 minutes is one of the bigger attractions to CRK for me.

Great info guys! I can attest to the frame lock design being very sturdy.

I can attest-I've been carrying & using Benchmade Axis Lock folders for over 10 years and not once has ANY of my knives slipped. That action is rock solid!

I like that benchmade puts their stuff out there for people. I don't think I'm going to be putting 1000+ inch pounds of force on the spine of my knife or 1400 on the blade any time soon. It seems it's plenty strong for any normal use, and is just so damned ergonomically friendly to open and close.

Having the spyderco PMII for a while, I've grown to very much love the compression lock on it. It feels rock solid when locked, and I've adapted software to be able to flick it open and closed almost as fluidly as the benchmade. It just requires a quick hand-shift to move my index finger to the lock on the compression lock to disengage it and flick it closed.

A long time ago I carried a Buck 110 folder. I can't imaging a stronger lock, coupled with the relative impossibility of accidentally unlocking the blade while in use.

It regularly wore holes through my pants, and is way too heavy for EDC for me. Besides, I've been seduced by the Benchmade Axis locks, with superfast one-hand opening and closing.

Liner locks always struck me as being susceptible to unlocking while in use; Axis locks are also not foolproof in that regard, but the utility of one-hand operation overrides that aspect, for me at least.

The Paul locking system is useful for quick one-handed deployment; I suspect it's fairly strong, but a bit complex to manufacture, due to close tolerances. This might render it unfit for service in a crud-filled environment. I can't say from personal experience, as I seldom carried one.

Obviously, my viewpoint is closer to personal utility and ease of operation rather than brute force on the locking mechanism, but under the conditions I've used my knives, the only problem I've experienced was with a liner lock. It didn't fail, except insofar as it closed the blade without my desire to do so.

The RAO extrema is probably the most secure, but it requires you to screw in the locking pin.