locks that FAILED -- tell us your story

Oct 24, 2004
We talk a lot about "strong locks" and "no bladeplay" but I would love to know situations where a lock actually failed.

Do you have situations you ran into where a liner lock, framelock, backlock or whatever failed?

What happened?
I think that linerlock twist happens to most linerlock fans sooner or later. You twist, and the knife folds.
It's happened to me a couple times, but with any consequences. (except my disillusionment of linerlocks)
I had a Buck back lock fail on me some time ago... But I was abusing it at the time :grumpy:
You know, I've never had a lock fail on me. Of course, I usually use a slipjoint in public, so I'm used to thinking of folders as non-locking. Matter of fact, I like the dramatic "thunk" that linerlocks get, but I really don't test my luck with them. If I have to pry/twist, its a fixed blade. At least if I break that I have a cool story to tell.

Hi Cognitivefun.

It is just my opinion, but I've been around a lot of locks for a long time.

All locks can be built to be strong and reliable. Reliability is more dependent on the engineering, materials and the QC of the company making the knife.

Not the type of the lock.

Some lock designs are more difficult to manufacture correctly, but.......

In reality, ALL locks will fail under one condition or another. For one it's twist, for another, it's dirt or lint, a 3rd will become faulty with enough wear, on the 4th, a spring fatigues, on a 5th, a pin shears and on some, they are just plain worn out.

I always recommend an occasional light spine wack to "test" the lock. Kinda like checking the oil level or tire pressure. Better to know on the test, then to suffer the inconvenience (or serious damage) of a cut. If it fails, clean it and try again, if it fails again, retire it. Once a lock fails, it is not likely to fix itself.

I have a problem with CRKT. If the phrase "once bitten, twice shy" applies to knives, I'm four times shy with CRKT. The worst was a Red Dog (Crawford designed). This thing had absurd amounts of blade play, and there was at least a 1mm gap between the liner and the blade when "locked". It failed on me (simply slipped unlocked), and I got a 3 stitch cut, and permanent nerve damage in my index finger. The other one was a dinky little lockback (which incedentally came free with the Red Dog) that wasn't any more secure than a slipjoint.

So now I'm leery of both linerlocks and CRKT knives. I'm sure an M16 is perfectly safe to trust, but I still won't own one. I don't own any linerlocks anymore, but that's not really the result of my mistrust, but rather the fact that I just don't own any. If I did, they'd be quality ones like Microtech or Spyderco.
I've had all my microtech liner locks "fail" after their first few spinewhacks, after which they set and don't fail anymore. In real world use though I've only had one lockback fail due to pocket lint. Actually cutting things I have a little trouble with my midlock Endura and cutting corrugated cardboard, the swell of my palm contacts the lock bar cutout and the resistance of cutting the cardboard (regardless of sharpness) tends to get it halfway to being unlocked, you can feel the blade wiggle up and down signifigantly during the cut as the pressure from my palm changes.
Never had a lock fail on me, but I never trust them, either. I treat all folders as if they were slipjoints.
I treat all folders like tools, and hence, I use them to cut dense and grippy material (like cardboard) that I would not cut with slipjoints. I can't carry a FB in my state, so that kind of makes it a moot point.

Lock failure... Primarily linerlocks of the 0.050" variety, but I've had several in the 0.063", 0.080", and 0.090" class fail consistently, simply, and catastrophically. Bad tang geometry...

Then again, I use liner and framelocks the most. I haven't had a lockback fail on me, but I rarely use them. I haven't had an AXIS lock fail and I use one on a regular basis. The plunge/button lock can get gritty and fail due to getting stuck in the open position.

UnixDork said:
Never had a lock fail on me, but I never trust them, either. I treat all folders as if they were slipjoints.
that might be bad too. You have to respect gravity.
Most linerlocks have very loose pivots.
I had a Timberline knife fold up one me once, when I first got it. I wasn't using my head and figured it would operate like my other liners, when in reality it needed to be opened a lot harder to fully bring the liner over. Only minor damage.

And my brother cut himself with his Axis BM. He must have pulled the lock back drawing the knife one way, and when he pushed the other way the bar must have been too far back. Nothing a couple butterfly bandages couldn't fix up ;)
Thus far, I have never had a lock fail during actual use. Part of that is that I grew up using slip joints and I have gotten a nasty cut when a slip joint closed on me, (my own fault for doing something I shouldn’t have done), so I tend to treat any folder as a slip joint. I have had several liner locks fail spine whack tests however and I am very shy about liner locks and to a lesser extent framelocks. I have found with my knives that when you take apart a liner or framelock, everything has to go together just right for it to work properly. Having spent the last 20 years working as an engineer in a manufacturing environment, I realize that to get everything right all the time is impossible and in my humble opinion this can make liner/framelocks more prone to problems. Blade play can be a serious issue with liner/framelocks because can directly effect a locks performance. Lockbacks are more tolerant of play as long as the geometry of the engagement area is correct. As Mr. Glesser said, given the wrong set of circumstances, any lock can fail. I carry a folder instead of a fixed blade all the time, but if I felt my life might depend on my knife, I would carry a stout fixed blade.

no actual 'failures' of locks, yet, but the closest i got to that is were the locks disengaged during heavy bush-clearing on the shore where i was fishing.
i also started to dislike liner-locks lately because when used hard the pivot always loosens. the worst situation is where your pivot loosens in the middle of nowhere, and all it can be adjusted with is a Torx-bit.........

liner-locks that had their pivots loosening up regularly on me:

- buck strider, all 3 i owned actually
- spyderco military
- al mar sere 2000

liner-locks that had their locks disengaged, almost closing and cutting me:

- buck striders

the same, but with lockbacks/frontlocks:

- spyderco police (WITH david boye dent by the way.......)
- buck 110

admitted, i'm hard on my knives, even my folders, and i regularly use them for slashing/chopping plants and thin branches on the shores of my fishing-locations. white-knuckling is often involved. :eek:

But, I was useing it to split wood at the time so does that count? :confused: I did repair it though so it's ok. :D
I too treat all of my folders as if they were slip joints. I had a Spyderco Native (with a Gin-1 steel blade) close on me. I was cutting some plastic banding and I must have twisted the knife in the process. The blade began to close. The blades finger choil saved me from getting cut. I have never had a problem with any other Spyderco knives. Great products. :) One thing that I don't like about certain lockbacks are the one's with a rear locking bar. The mid locks seem to be less prone to accidental closing.
dennis75 said:
i also started to dislike liner-locks lately because when used hard the pivot always loosens. the worst situation is where your pivot loosens in the middle of nowhere, and all it can be adjusted with is a Torx-bit.........

Loc-tite is your friend. :)

Always blue though and just a dab - never red unless you want a permanent pivot.
I've never had a lock fail on me while using the knife, but I've had two knives fail a moderate spine whack test. One was a well-used '80s vintage Case lockback, and the other was a new Camillus Cuda Maxx 5.5 (framelock). I've tested 3 other Cuda Maxx knives that all passed the whack test.
1 ) A buck 110 , failed a spine whack , could be released with light finger pressure on spine .

2) 3 midlocks , 1 Kershaw , 1 Spyderco , and 1 Custom experienced experienced spring or lockbar breakages .

3) A spyderco Dodo ( early production ) failed under minor finger pressure on the back of the blade .

4) A CRKT liner failed to engage on three consecutive attempts .

5 ) Numerous liners , production and Custom have failed light spine whack tests at the pre purchase stage .

None of these failures occured under heavy use , or prying , or in torque applications . In all cases the knives were clean and well Lubricated at the time of failure .

I have never had a problem with a Benchmade Axis lock , a Spyderco compression lock , or any of my four framelocks .

While I own several linerlocks , some of which I'm very fond , I dont trust any of them . I have never had problems with Benchmade liner locks .