Are liner locks easy to use / safe?

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Chewy1

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I've been doing some reading, and one could get the impression that linerlocks fail an awful lot. Are your standard Buck linerlocks likely to fail? This would not be heavily used.

Also, are they difficult to use? I'm looking for one for my wife, and she does not have strong hands. Picture the strength of a 10 yr old boy, I guess.
 
well, i guess it depends on the knife. I have had only one knife fail me and it was a cheap knife from walmart. The lock was crap. now on my Zero Tolerance 0200, I have never had the lock fail on me, or for any knife for that matter (except the one). It really depends on the knife though. I have one buck that I have not really used hard and the lock never failed me. Bucks are good knives I think. They are not top of the line but not gerbers :) I think they are good knives. liner locks can fail with enough force. They are really easy to use though.
 
Cheap chicom linerlocks? Yea...probably...but I can't speak from experience since I don;t buy them or keep the ones given as gifts.

Buy well-made knives from reputable and concientuous knife-makers. Production companies that make nice ones, to name a few, include Benchmade, Spyderco, Kershaw, Strider, Buck, etc, etc. While there's always a story or three of a linerlock failing on someone during actual use, the majority of the locks are going to fail while someone is holding the folder on their knee and hacking away at the spine. A testing which is senseless and irrelevant to the designed function of a folding knife.

Aside from the BM AXIS lock, the liner lock is my all-time favorite compared to slipjoints, lockbacks (possibly holding an edge in a lock failure testing), and frame locks.
 
Chewy1 said:
Also, are they difficult to use? I'm looking for one for my wife, and she does not have strong hands. Picture the strength of a 10 yr old boy, I guess.
Click to expand...

Most major knife companies liner-locks are going to be safe, but I have personally had more "slips" with liner-locks than any other type.

For what you describe above, the Benchmade AXIS lock jumps to the foreground to me.

Simple to use, very secure but requires little strength to release.
 
I have had a couple of liner locks that (for some reason) lock tight when open making it take a fare amount of force to release the lock. They sort-of "jammed" tight you might say. The vast majority of my liner locks work well and easily. I have never had one actually fail but I do not work my knives very hard.
 
I've never known women to have a problem with a slip joint in use. They understand you can't do stupid stuff with them, and don't appreciate the complication of a lock that might actually cause a cut when closing. So avoid the problem entirely and get her a nice slip joint.

Now, guys (like us) who try to use them as screwdrivers, pry bars, or splitting wedges, well, we have it coming.
 
I've never quite understood the problem some folks have with liner locks. I like them because they lock up tight and are one of the easiest lock designs to disengage. Sure, with enough pressure on the spine, the lock may disengage on its own, but other than testing the strength, why would there be any pressure on the spine to begin with? Anyone carrying a folder that is sharp enough to cut things with should know better that to do anything but cut with it(enter the "spine-whack test").

I can't speak for everyone, but I have never had the occasion to put any pressure on the spine in any circumstance. We have all cut ourselves enough times to be aware of where the blade is going to go if it slips off the cut.

As has been said dozens of times on this forum, if you need strength, get a fixed blade, if you need to pry, get a pry bar.

I'm not trying to be a jerk or anything(although I usually am), it's just that I have always felt the lock on a folder was there to hold the blade open without [much] play, not to keep it from closing on your fingers, that's what our brain is for.
 
They can be. It all depends. Like anything there are many differences from one brand to another and in some lines differences from one knife to another even in the same models.

Many folks generalize not knowing the little intricate details that make up how the lock works in the first place, let alone what makes one better over another.
Just cutting down a cardboard box puts spine pressure on a blade spine and depending on sharpness sometimes its a lot of spine pressure. You can find many references to liner locks defeating while cutting down cardboard around here and on other forums.

First thing to look at is the contact pitch angle where the lock meets the blade. Its not rocket science.

Look at a good liner lock. Gene Baskett, Vice President of the KnifeMakers Guild makes an excellent liner lock. Its shorter but still plenty ample for large hands. Its thicker with lots of rigidity for a stable flex resistant frame. The pitch angle is 7 degrees on each and every one consistantly across the board from one to the other and so consistant he doesn't even need the knife to make a replacement blade.

I'll be perfectly honest with you. Regarding the contact angle knife makers call the 'interface' I see a lot less problems in the shorter liner locks than I do the longer ones. The longer ones do flex easier and its easier to get a lot more leverage on the longer handled longer bladed models which equates to a lot more pressure on the contact.

Look at others. If you liner lock lovers want to shout at me for being the messenger do so but take a number and stand in line.

I see a vast variance in pitch angles from manufacturers and makers. Kershaw's factory knives mirror Baskett's customs and seem very stable to me. Look at theirs compared to Spydercos, BenchMades, Emersons and others and you'll see the variance.

A 7 degree angle is simply going to be more stable than a 15 degree angle under pressure. When I get two knives made in the same year that are the same model sent to me for something and can note that one has a 10 degree pitch angle for the contact and the other has a 15 degree and get a third later with a 12 degree and see yet another companies knives that have consistantly shown me that they make them all as close to the same more reliable angle that works better under pressure I'll go with the better one under pressure.

My fingers mean enough to me to do that. Basing finger safety and lock security on blind faith is not a good idea no matter how much emotional attachment you may have for a product or maker or how good or bad you may think a lock type is. Know the facts and if you don't know them learn what to look for and how to test them for each type folder locking device made.

Generally speaking, I like 7 to 10 degree angles on my own liner lock contacts. Of course there are many more factors that make up a good vs bad lock of this type. The foot print or contact surface area of the lock itself that relates to the blade to support it has everything to do with wear rate as well as where the contact actually is on the lock face. It can also relate to how a lock sticks in place better on one vs another or why one slides off the contact easier over another among other things and it can directly relate to how the blade feels when opened and whether it rocks or not or is locked up tight. http://www.bladeforums.com/forums/showpost.php?p=5171804&postcount=11

I've said enough. I better shut up before someone comes in and says I'm just trying to stir the pot or drum up some sales or something.

STR
 
Having grown up with slipjoint folders, I know if I'm polking or jabbing something with the point of the knife there is a chance I may put pressure on the blade in the wrong direction and it will start to close. Most of the time when you are cutting something the pressure on the blade is in a direction that keeps the blade open.

Some liner locks are much better than others, but I'm not as trusting with liner locks as I am with most frame locks and AXIS locks when it comes to using the blade in a way that may cause the blade to want to close. If I need to do some hard jabbing I much prefer a fixed blade knife.

Rich
 
STR touched on it, but I think I'll say the following: Buck is a fine and legendary knifemaker; however, anything made by humans can have imperfections and fail. The less things to go wrong, the less likely they would be to fail. An example would be a fixed blade knife won't likely fold back on your child.

My main point is this: take this opputunity to teach your child how to use the knife correctly. He should always cut away from himself, and be taught to not bind the knife or take a chance on the lock, no matter which one you chose, in case it fails. I wouldn't scare him, but just tell him, "it probably won't fail, but just in case here is the proper way to cut."
 
Chewy1 said:
I've been doing some reading, and one could get the impression that linerlocks fail an awful lot. Are your standard Buck linerlocks likely to fail? This would not be heavily used.

Also, are they difficult to use? I'm looking for one for my wife, and she does not have strong hands. Picture the strength of a 10 yr old boy, I guess.
Click to expand...

Your wife may prefer one of the Benchmade folders with the AXIS lock. Usually an AXIS lock requires very little strenght to use. Also, some people feel uneasy putting their thumb in the path of the blade when they disengage a liner lock (or frame lock)...even though they have control of when and how fast the blade closes.

With the AXIS lock you don't need to put a digit in the path of the blade.
 
I have about 30 liner locks and a couple bucks. I have never had a liner lock fail on me.

Dave
 
I own a lot of linerlocks , a few of which I do not fully trust so I am aware of that when and if I carry those certain knives.

Do not let popular brand names fool you , one of the linerlocks I have little faith in is a Benchmade, that of course says nothing about the other Bench's I own , it's just particular model.

I will always try to tune a liner or frame lock to my tastes and usually succeed.
This is especially important for me on the lower cost knives like CRKT M16-13Z , once I tuned the linerlock a bit , I know feel more comfortable in using it , that it will not close on me.
 
Pitch angle. Nice phrase to describe the intersection of the blade and liner.

I have had liner locks fail, they were from large American manufacturers. And the pitch angle was certainly a lot steeper on them than others. Including the warranty replacement.

I'd add that the length of the active liner lock section has some affect on pitch angle because of the location of the virtual axis. They don't all exactly pivot at the end of the cutout, and don't really rotate there like a hinge, anyway. Short liner leafs seem to have steeper pitch angles, just because of the arc they travel.
 
I like liners less and less on my knives. I had liners failed on my A-F combat folder, CRKT M16-04d (or 14? don't remember the number), I tried to change the place of contact of liners with blades, but it didn't help. Liners on 2 of my buck 880sp even don't fix the blade and it has vertical move.
I like liners on such knives as spy millie and al mar sere 2000 where blade isn't sharp at the beginning (choil?), so you don't cut if finger meets the blade when close.

I like axis more.
 
You can do some testing to see that your knife is actually functioning as it should quite easily. http://www.bladeforums.com/forums/showthread.php?t=494549 (2nd post)

To see some variance in what I am speaking of regarding liner lock contact angles just a good site that sells high quality folders can show you the angles and the variances you can typically see in even the higher dollar folders made out there. Steel Addiction has some good photos of their knives for sale. You can look at one and then compare it to the picture of another contact interface where the lock meets the blade when you open the knife and see exactly what I am referring to. You don't have to know the percentage of the angle to see the differences.

A lay person is not going to know the little intricate details about the relationships of the lock and the blade and you really don't need to know much beyond buying one that is going to pass some simple tests you can do before buying or after without changing the knife. Generally speaking if the contact angle looks like the lock could just slide right off the blade like you slide down a sliding board then it is probably very possible that this can happen. If the lock looks like it can contact and stick well to a flatter rest spot on the contact verses one that is ramped steeply it is not going to take a lot of thought to figure out that it will likely be more secure. This is especially true when you put the blade under pressure or tap it where the spine of the blade hits something hard which can cause the lock to give or move. Many guys tap the toe of their boot once they move their fingers out of the way. This won't do any damage and can be done quietly without damage to anything so long as it is taps and not 'whacking' that you do.
STR
 
Liner lock knives became real popular at the beginning of the Tactical Folder Era, and greater popularity brought on a greater number of knives to the market. This led to a LOT of cheap, poorly made linerlocks flooding the market. The liner lock is very easy to produce if you don't care about quality or longevity, and a LOT of the oversea's liner lock makers jumped on the bandwagon and started producing liner lock knives to fit that mold. A well made liner lock knife that is geometricaly correct at the locking interface should present no more danger than any other locking knife. The way you use it can cause ANY lock to fail if used incorrectly. I have two liner locking folders, a ZT0200 and a custom Jeff Hall large Bounty Hunter and trust both of them to work as they were designed to work. There is nothing mysterious or magical about a liner lock, its simply a matter of correctly or incorrectly building it.

That is my take on liner locks.:)
 
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