Are linerlocks really unsafe?

Like virtually any product, the vast majority of "accidents", incidents, and/or failures take place when the operator chooses to use the product in ways for which it was not designed. And frequently, that single improper usage can permanently ruin the product or feature so that it fails every time it's used after that, even when used as described or prescribed.

A coat button isn't inherently dangerous, but if somebody's 3-year old finds one on the floor, decides it looks just like a piece of candy, and chooses to use it as such, there's going to be a problem.

I'm not sure what a "spine whack" is; but I can imagine, and I'm quite certain I've never read any literature accompanying my knives that recommended that particular activity. And, what might have been a perfectly safe and functioning knife may have been turned into an unsafe one simply by that 1 act.
 
I prefer liner and frame locks to back locks. Yes your thumb is coming across the handle but generally the part that would contact your thumb on closing is the choil or unsharpened portion of the blade which is not a problem.

I have to wonder what people are doing with their knives that would make anything but a really terrible lock fail. OK some people use their knives HARD, but really shouldn't this pressure be against the CUTTING EDGE of the blade versus the back to make it close? Maybe it's just me, but growing up my first knives were all slipjoints, I was taught you direct all force against the cutting edge, in essence any failure of design would make the knife open more not close on your hand. The videos of CS knives where they hang weights off the handle, or use them as monkey bars--are people actually DOING these things out in the real world, and if so why?
 
MassMatt said:
I prefer liner and frame locks to back locks. Yes your thumb is coming across the handle but generally the part that would contact your thumb on closing is the choil or unsharpened portion of the blade which is not a problem.

I have to wonder what people are doing with their knives that would make anything but a really terrible lock fail. OK some people use their knives HARD, but really shouldn't this pressure be against the CUTTING EDGE of the blade versus the back to make it close? Maybe it's just me, but growing up my first knives were all slipjoints, I was taught you direct all force against the cutting edge, in essence any failure of design would make the knife open more not close on your hand. The videos of CS knives where they hang weights off the handle, or use them as monkey bars--are people actually DOING these things out in the real world, and if so why?
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Here's a video of Allen Elishewitz basically doing the same thing:

http://www.youtube.com/watch?v=yJ1moCHqa6E

I see how this might make sense from a purely comparative standpoint - This model by this maker made of these materials with this type of lock resists X pounds before breaking (now repeat with others).

From a practical standpoint, it makes no sense at all. I carried a Douk Douk for several years and while it would "fail" this kind of test no one would learn anything about its practical or safe use.

I believe the problem is there are a lot of people claiming linerlocks are unsafe, claiming they can fail easier than an axis lock or back lock or whatever, and as a result companies/makers are producing videos like the Cold Steel video (and the Elishewitz video) showing how much pressure can be placed on the lock in the wrong direction before it fails. Some consumers apparently dig this stuff as I am seeing more and more spine whack tests (search for "spine whack" on YouTube) and whenever these produce negative results the conclusion is that the lock is unsafe.

Anyway, I'm still interested in seeing linerlock failures that don't result from spine whacking or accidental disengagement of the lock with the thumb. My guess is I'm not going to see any, as some of you rightly pointed out a slipjoint won't fail during normal use because you would never put pressure on the blade that would cause it to close during normal use. The same applies to any folder and lock design cannot prevent stupidity.

Thanks again everyone!
 
midnight flyer said:
I was wondering, when you say the most, how many liner lock failures have you had? What were you doing when these failures occurred?

Robert
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Only three out of a couple hundred folders, and just one really, really cheap lockback. The knives were all under $100 retail, and they failed from steady pressure on the spine or light tapping. Things like inserting the blade to cut cable ties between wire grating or knocking the mud of the soles of my boots happened to cause the lock to slip.

I have owned and used many slipjoints. I don't need a folder to lock to use it safely, but if I am going to pay for a knife with a lock, then there's no reason to settle. Most locks operate with one hand, most come in both light and heavy knives, most open and close easily as intended. If I can't white knuckle, torque, tap, or squeeze a lock to disengage accidentally, then I like it better than one I can.
 
hardheart said:
Only three out of a couple hundred folders, and just one really, really cheap lockback. The knives were all under $100 retail, and they failed from steady pressure on the spine or light tapping. Things like inserting the blade to cut cable ties between wire grating or knocking the mud of the soles of my boots happened to cause the lock to slip.

I have owned and used many slipjoints. I don't need a folder to lock to use it safely, but if I am going to pay for a knife with a lock, then there's no reason to settle. Most locks operate with one hand, most come in both light and heavy knives, most open and close easily as intended. If I can't white knuckle, torque, tap, or squeeze a lock to disengage accidentally, then I like it better than one I can.
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OK, thanks for the clarification. Makes sense to me! :thumbup:

Robert
 
knarfeng said:
The reputation of linerlocks for failing comes from their use on low-end knives. Liner locks can be the least expensive lock to make, so they get used a lot on cheap knives. The locks on such knives are not well made, and they fail. A well made liner lock is quite reliable.

The truer statement might be, "cheaply made linerlocks are prone to failure."
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...this is your answer. period, end of story...
 
Like some others have said, a lock is a safety, if you are using a knife within what it is made to do you shouldn't have to have a lock. Also, all the hype about frame locks is just an opinion to me, I haven't found a frame lock that can out perform a good liner lock.
 
Test your individual knife and find out. I had two Kershaw Barrage framelocks, and when tested one failed with a ridiculously low amount of pressure, maybe 10lbs, the other held up to about 50 lbs. I tested one of my Gerber liner locks and the thing repeatedly popped off with about 10lbs of pressure. Both of these failed with the lock retracting, the blade could have closed on my fingers. I bent a CRKT liner lock over with about 25lbs of pressure (though in that case it warped out and the blade could not close into the handle, protecting my fingers but the knife was trashed.

Here's the test, put a bathroom scale next to your bench and vise. Pad the vice and lock the knife in it, edge up. Stand on the scale and start slowly pushing up on the handle, keeping an eye on the knife and the scale readout. Not terribly precise, but close enough for a comparison.

The only liner/frame locks I trust are ones that have passed my test. If I get to 50lbs and it hasn't failed I figure it should work well in the real world. My Kershaw Leek held over 75 and still didn't fail. I figured any more pressure than that was just plain abusive and unrealistic.

I have had one backlock - a Benchmade Pika (one of the early ones that didn't have a reinforcing liner), fail at less than 50 lbs, otherwise all my backlocks passed.

Frame and liner locks, and most other locks, can be very effective but all should be regarded suspiciously until some sort of test is done under safe conditions.
 
I don't trust liner locks at all. I don't even think it's always a matter of a knife being cheap, I can get the lock on my spyderco Millie in m390 to disengage just by squeezing the handle, and I have seen videos of people doing the same thing so it's not just me or my knife or me being an idiot.

I've never had a lock disengage on me while in use but I don't ever use folders for any hard work.

However I have gotten 4 liner locking folders to disengage On me just by squeezing the handle with a tight grip.

In my eyes a liner lock is the most unsafe lock out there. it's the weakest, most easily disengaged, and you have to put your fingers infront of the blade to close it. All that adds up to an unsafe lock.



Most people probably won't have a failure but with so many stronger and faster locks on the market, why chose the weakest one? If you are going to be using your folder for harder work go with a triad/axis/compression/ballbearing lock that has been proven to be stronger than the liner lock.
 
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KalEl said:
I don't trust liner locks at all. I don't even think it's always a matter of a knife being cheap, I can get the lock on my spyderco Millie in m390 to fail just by squeezing the handle, and I have seen videos of people doing the same thing so it's not just me or my knife or me being an idiot.

I've never had a lock fail on me while in use but I don't ever use folders for any hard work.

However I have gotten 4 liner locking folders to fail On me just by squeezing the handle with a tight grip.

In my eyes a liner lock is the most unsafe lock out there. it's the weakest, most easily disengaged, and you have to put your fingers infront of the blade to close it. All that adds up to an unsafe lock.



Most people probably won't have a failure but with so many stronger and faster locks on the market, why chose the weakest one? If you are going to be using your folder for harder work go with a triad/axis/compression/ballbearing lock that has been proven to be stronger than the liner lock.
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You should replace the term "fail" with "disengage". It lends much more accuracy to your opinion. On the Mlitary, if you apply enough pressure at the recessed portion of the nonclip side (specifically on the liner itself) of course it will disengage, that is what the recess is there for. Keep in mind, I'm not trying to change your mind, merely attempting to clarify your opinion as being that and not actual fact. Some people might read your post and fall hook, line, and sinker and take it as a factual statement. In addition, the knife was designed to be glove friendly, yet another reason to have an area where someone can quickly unlock the knife and close it safely without having to remove the glove. If the Walker Linerlock was such a miserable faiure across the board, no one would want to risk the liability of using it anymore, regardless of cost.
 
KalEl said:
I don't trust liner locks at all. I don't even think it's always a matter of a knife being cheap, I can get the lock on my spyderco Millie in m390 to fail just by squeezing the handle, and I have seen videos of people doing the same thing so it's not just me or my knife or me being an idiot.

I've never had a lock fail on me while in use but I don't ever use folders for any hard work.

However I have gotten 4 liner locking folders to fail On me just by squeezing the handle with a tight grip.

In my eyes a liner lock is the most unsafe lock out there. it's the weakest, most easily disengaged, and you have to put your fingers infront of the blade to close it. All that adds up to an unsafe lock.



Most people probably won't have a failure but with so many stronger and faster locks on the market, why chose the weakest one? If you are going to be using your folder for harder work go with a triad/axis/compression/ballbearing lock that has been proven to be stronger than the liner lock.
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Your final comment is duly noted - I have been interested in Spyderco's compression lock and would be interested in trying it out. However I haven't ever disengaged a linerlock by squeezing it. We're obviously handling them differently because no inside-out pressure is placed on the lock bar when I'm holding it. I'd say the opposite is actually the case, but again we're probably holding them differently.

Here's another thought - if the pivot screw became loose enough, would it possibly make the blade wiggle enough to disengage the lock? And would this ever be an issue during normal use?
 
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If I was going to stab into something very hard, I would want a compression lock, lock back, axis lock, or a frame lock.
 
RevDevil said:
You should replace the term "fail" with "disengage". It lends much more accuracy to your opinion. On the Mlitary, if you apply enough pressure at the recessed portion of the nonclip side (specifically on the liner itself) of course it will disengage, that is what the recess is there for. Keep in mind, I'm not trying to change your mind, merely attempting to clarify your opinion as being that and not actual fact. Some people might read your post and fall hook, line, and sinker and take it as a factual statement. In addition, the knife was designed to be glove friendly, yet another reason to have an area where someone can quickly unlock the knife and close it safely without having to remove the glove. If the Walker Linerlock was such a miserable faiure across the board, no one would want to risk the liability of using it anymore, regardless of cost.
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I changed "fail" to "disengage".

The liner lock isn't some abysmal failure by any means, it has simply been surpassed by newer locks. 20 years ago the linerlock was a huge innovation in knives and it has served well as a lock on millions of knives BUT IMO, it is outdated and no longer has any advantage other than being easy to manufacture.

Lets look at the factors that make a good lock

Speed- ability to rapidly close and open the knife
Strength- how much pressure can the lock take in a variety of directions without breaking or disengaging
Easy of use- How easy is it to close? Can you close it with one hand?
Safety- Do you have to put your fingers infront of the blade to close it? In a non ideal situation could I safely operate the lock? Does the lock disengage only when I want it to?

Now lets access the Walker liner lock
Speed- The liner lock is one of the slowest locks out there for closing. The axis lock, ball bearing lock, Blackie collins lock, and compression lock to name a few, can all be operated faster. Speed of opening- you can't flick open a liner lock as readily as you can a compression, BB, or axis lock. I can open and close an Axis lock faster than I can open and close a liner lock.
Strength- The liner lock is without a doubt, the lock that can take the least amount of pressure before failure. The axis lock, BB lock, Compression lock, and Triad lock have all been PROVEN to handle a higher load before failure.
Ease of Use This is where the Michael Walker made his great contribution to the knife world. The Liner lock, when invented, was a big improvement in one handed closing and general ease of use. Nowdays I don't think its any stretch to say that the axis lock is easier to use than the liner lock. I can an axis lock knife open, use it, and the close it in a split second without looking at the knife. I can't do that with a liner lock, It simply takes longer to close and isn't as easy to use overall. Newer locks like the Axis and BB lock are also ambidextrous. Ever need to close your liner lock with your non dominant hand? It takes some time.
Safty- The frame lock and liner lock suffer from the same issue, you have to put your fingers infront of the blade to disengage it. New locks like the Comp/BB/Axis lock have eliminated that problem. Another issue I have with the Liner lock is that they can be much more easily disengaged during use than a triad/BB/axis/Compression/framelock. Like I have said, I can disengage many liner locks just by squeezing them. I can't do this with any other lock.

None of this is meant to be a knock on Michael Walker, his lock or anything he has done. Michael Walker has been a great innovator in the knife industry and the liner lock was a major breakthrough and has served countless users around the world.

I just think that today there are better locks out there. VHS was at one time an amazing breakthrough in the film industry. But now we have Blu Ray.
 
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CQC86 said:
If I was going to stab into something very hard, I would want a compression lock, lock back, axis lock, or a frame lock.
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If I were going to stab into something, I would not be using a folder.
Oddly enough, in 50 years of using blades, I have never found it necessary to stab something.
 
Kalel, I enjoyed reading your response. Thank you for taking the time to reply. I understand and respect your postion on the matter. :thumbup:
 
I try not to stab a folder into anything unless I have to. When I do, I prefer a flipper because in the chance that the lock disengages, the flipper tang will prevent the knife from closing on my fingers. At worst, I'd have a nasty pinch from the flipper tang, maybe even some broken skin. That said, I am 100% confident in my linerlock flippers. This is what I prefer and the only type of knife that I buy, excluding fixed blades.
 
I have no problems with a well made linerlock folder. The majority of my knives have this style of lock. One thing to note is something Kal-El mentioned with the Spyderco Military. A linerlock knife without liners, or one liner, or even 2 thin liners, or going to be able to have a hard squeeze, in the right place, flex the liner and perhaps cause it to disengage. This is why I like thicker liners, but it still must have the correct geometry between lock face and blade tang to be effective.

Another thing that I have found is that some linerlock knives arrive without much bend in the linerlock itself and this can/will cause it to disengage to the left of the blade when even light pressure is applied. I once had a custom linerlock from a well known maker that I could cause to disengage by applying light pressure, letting off, reapplying pressure, letting off again, and watching the liner march to disengagement the whole time. I took it apart and slowly begin to add more bend to the liner, put it back together, try it out, and it took care of the problem and the knife was as tight and no pressure applied to the back of the blade would cause disengagement. This process is one that you should take tiny steps in doing it so as to not overdo the bend.

But the bottom line is that I trust a well made linerlock folder, of the type I currently have, that meet the above conditions.

Kal-El, while I do not agree in whole with what you have said, like RevDevil, I can respect and consider the things you have written!:)
 
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