which folding knife locks will fail? when stabbing forces are applied....

jbmonkey

jbmonkey

sure sure
Platinum Member
Joined
Jun 9, 2011
Messages
29,967
first off.....to clear the air......this isn't a question about which lock will allow me to be a billy badarse and stab the most people without lock failure. a folding knife is a bad tool for stabbing anything, and likewise i never have a reason to stab anything. this isn't about that, it's about me trying to understand the forces applied when a folder might be used to stab something and whether those forces will make a lock fail because of it's design.

what got me thinking about this was a post on here i found doing a search on something else where a guy said he almost lost a finger from a backlock failing doing stupid stuff with it and using it to stab something.

there is often discussion on here about locks failing spine whack tests and things of that nature. i'm much more interested in ya'lls thoughts on which locks would fail easier from stabbing forces rather than spine whacks and weight hanging on the end of a handle of a knife in a vise. maybe those forces are the same and those "tests" for a lack of a better term show actually what i am asking? if that isn't the case....

i'm gonna eliminate slip joints for obvious reasons. let's talk...

-tri-ad
-backlock/midlock
-liner lock
-liner lock with walker/lake lawks setup
-frame lock
-compression lock
-button/plunger lock

any other common lock i forgot about? which would fare better and which would fail. for discussion purposes....yep a fixed blade will beat them all, no argument from me. also the quality of the knife will make all the difference i have no doubt of that. after i read an article on the walker liner lock and how allot of companies to this day get the angles/engineering wrong and that allows for the common failures we all read about. let's just assume quality of each lock is equal and top notch. thanks in advance for your input. looking forward to learning something new today......
 
I wouldn't feel confident stabbing a car door with any folder but if I had to bet my hand or fingers I'd stick with the Triad in a heartbeat
 
Last edited:
Benchmade 580 Barrage. Axis plus locking bar. A lock for a lock.
 
Wow, that's one heck of a question. And a good one. Though I think a person would have to be an engineer or a physicist to answer it properly as it involves physics (applied-force dynamics, torque, ect) as well as structural engineering. Sadly, I'm not qualified.

As far as opinions go, though some folders lock-up tighter than others, I'm generally of the opinion that if a folder closes on a persons fingers, it's that person that's to blame. I've been using folders on a regular basis for over thirty years from lockbacks to liner locks to framelocks, and while some have been "tougher" than others, none have ever accidentally closed on me. I thinks it's simply a matter of using a folder in a safe manner.

I consider a lock on a folder to be a luxury feature. It's nice that it's there but I wouldn't EVER want to bet my fingers on one, no matter who made it or how much of a "vault" it's reputed to be. No task is worth risking the loss of my fingers.

I supose in some type of emergency situation where a folder were all I had I'd want it to have the toughest, most reliable lock possible (whatever that is). But I almost always carry a tough fixed blade for "heavy" work, and though my prefered carry folders are somewhat tough (Al Mar SERE, Bradley Alias), I REALLY wouldn't want to have to try and chop my way through a brick wall or pry a door jam apart with one.

Sorry I didn't have answers for you. Just my own opinions.
 
P2P said:
Benchmade 580 Barrage. Axis plus locking bar. A lock for a lock.
Click to expand...

That's one of the very few locking systems I'm extremely confident in. Take a look at it, there's almost no way for it to fail if all your screws are in tight.
 
I have had lock back and mid locks fail on me(except tri-ad). The mids I figured out that I was squeezing the lock when I gripped it and disengaged the lock.
 
Other locks like the "monoblock" on cs' pocket bushman, the opinel's viroblock or the lever locks on navajas. Are you interested in those too? I have a lot of trust in the pocket bushman.

The only type of lock I ever have found to fail is the linerlock. Even when they don't get abused up to failure, they still develop play between the knife and the liner. Maybe I got just got faulty ones, or maybe I shouldn't have gone for the cheap ones.
 
I have also seen back locks fail from most likely squeezing the lock. Even seen a Triad close up again most likely from squeezing, but that was a spine whack. But it shows it can happen when the lock is placed under your hand. Some people say that isn't a failure since nothing 'broke'. But if a knife blade tries to sever a finger that is a failure in my book. I don't have much faith in liner locks these days. There are some that work great, but some don't. I think it would be the first to break or fail out of all the designs though. The frame lock would be right behind it depending on design and cutout placement. It might not close on you since gripping the knife holds lock closed. But it could fail with the lock bending at cutout and I still place after the liner lock in this regard. I think a button lock would be after that unless really beefed up. I would take the AXIS and compression if looking for the strongest.
 
Windex_ said:
I almost lost my pinky from a kershaw blurs liner lock failing.
Click to expand...


not to derail my own topic and start a discussion only about the liner lock, but can i assume you were stabbing something or was it doing something else when the lock failed? also since you have first hand experience with a failed lock......did the liner lock fail by unlocking or did the bar move across to the other side as it should, and buckle enough to close on your finger?

your experience is also interesting cause kershaw has this written right under the blur about the blur.....

ABOUT THIS PRODUCT:



Most knife injuries occur because of a poor grip on the knife. Kershaw's Blur solves the problem with a unique handle that features advanced materials to ensure a safe, secure grip every time—even under extreme conditions. The Blur also features incredible, multi-tasking performance, the highest quality materials, and the kind of good looks knife users will be proud to own. For smooth, one-handed opening, all Blurs are SpeedSafe® equipped. The Blur's 6061-T6 aluminum handle not only precisely fits the user's hand for a comfortable, secure fit, but Kershaw also CNC-machines each handle to accept textured Trac-Tec inserts for a secure grip."
Click to expand...


guess that wasn't true in your case. thanks for your feedback and experience, sorry about the injury.
 
Gobbo_the_civet said:
Other locks like the "monoblock" on cs' pocket bushman, the opinel's viroblock or the lever locks on navajas. Are you interested in those too? I have a lot of trust in the pocket bushman.

The only type of lock I ever have found to fail is the linerlock. Even when they don't get abused up to failure, they still develop play between the knife and the liner. Maybe I got just got faulty ones, or maybe I shouldn't have gone for the cheap ones.
Click to expand...

yes, Sir all of them. thanks for bringing those versions up.

it seems to be a pretty common theme on forums liner locks failing and allot not trusting them. i read a great article written by Bernard Levine about Micheal Walker and his liner lock design, and in it he somewhat quoted Mr. Walker as saying he was glad most knife makers were using his design, but was not thrilled they weren't doing the angles correctly and allowing them to not function as he designed the lock to work. it was a eye opener.....maybe it's not the lock design that fails so easily it's the makers engineering?

also in that article was an interesting point about another lock Mr. Walker designed earlier than the liner lock and never patented, and a maker (when the article was written i assume) was using it and calling it their own, and Mr. Waler was not too happy about that........but there was no naming of names or the lock design in question.
 
I had a couple of close calls with my spydie police (before the boye dent) it was caused by me sqeezing the handle and the pressure released the lock, not all the way but enough for me to notice movement in the blade. It does not normally concern me because I have not found anything that I would pierce than use the spine of my knife to cut. My close calls came when making a divot in a plank to start a fire. My mistake for not paying attention and putting wrong the forces on the knife.
 
I just had a liner lock on a Boker (Brand New) it was not working well when I got it. It went back.
 
first thanks Gents for all your feedback. i'd thank ya'll individually, but that would eat up too much bandwidth.
 
Maddogg774 said:
I have had lock back and mid locks fail on me(except tri-ad). The mids I figured out that I was squeezing the lock when I gripped it and disengaged the lock.
Click to expand...
This. Has happened to me with liner locking knives too. I can grip an Endura several different ways that make it disengage if my hand shifts at all. I don't have that problem with the Delica though, which is good because it's one of my favorites.
 
Don't do dumb stuff with your knife! Yes, you can stab with a folder. Yes, it may fail. Like any tool, it has its intended purpose-which it works best at. The purpose of a folder is to give you a larger knife that essentially halves its size for easy carry, and space saving. Anything mechanical can (and will) eventually fail. Know the limits of your equipment, and stay well within its capability.
 
RRR1977 said:
Don't do dumb stuff with your knife! Yes, you can stab with a folder. Yes, it may fail. Like any tool, it has its intended purpose-which it works best at. The purpose of a folder is to give you a larger knife that essentially halves its size for easy carry, and space saving. Anything mechanical can (and will) eventually fail. Know the limits of your equipment, and stay well within its capability.
Click to expand...

Yep exactly what I already covered in my first post. it still would be interesting for me anyways to understand how a folding locking knife would or could handle that kind of stress.
 
You must log in or register to reply here.
Back
Top