Liner and Frame Lock Reliability?

allenC said:
True.

But in my experinece, liner-locks (without the LAWKS feature) are inherently more prone to failure than lock-backs, Axis-locks, Compression-locks, Ball bearing locks, Arc-locks, Ultra-locks, button-locks, and Balisongs.

So, with so many other locking knives available, I really can't see a need to buy a liner-lock.
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on productions, maybe but a lot of the top custom SD folders are liner locks (ie emerson, pat crawford, etc) a LL needs close tolerances and the customs can have closer tolerances than productions. and probably 90+% custom LL dont have lawks, mostly CRKT's have that and most of them need it lol.

some production LL's arent too bad, EKI, spyderco, BM, all pretty good.

just depends on the make and model imho, nothing wrong with a properly made and fitted LL.
 
SIFU1A said:
on productions, maybe but a lot of the top custom SD folders are liner locks (ie emerson, pat crawford, etc) a LL needs close tolerances and the customs can have closer tolerances than productions. and probably 90+% custom LL dont have lawks, mostly CRKT's have that and most of them need it lol.

some production LL's arent too bad, EKI, spyderco, BM, all pretty good.

just depends on the make and model imho, nothing wrong with a properly made and fitted LL.
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It's not just the tolerances, it's the very nature of the liner-lock (frame-locks too).
Not only does wear over time change the geometry of the locking surfaces, but also the amount of force used to open a liner-lock or a frame-lock, and the amount of cutting force applied, affect the lock-up.
True, the better ones have a ramped tang to adjust for wear, but it can only account for so much wear.
That's why lock travel across the tang is of real concern to most liner-lock users.

And then there's the ball-detent...
Alot of folks like liner-locks because they are so smooth and easy to open.
This is mostly because they have no back-spring and you only need to apply a tiny amount of force to overcome the ball-detent.
Once the blade is moved only about 1/16" the ball-detent is free of the divot in the blade, and there is nothing to keep the knife from opening.
I've only had two knives open inside my pocket: a Compression-lock folder and a liner-lock folder.
Lock-backs, liner-locks with back-springs (like Victorinox uses), and the Axis-lock require much more blade travel to overcome the spring provided resistance in order to open.
 
i'm not entirely certain that the lock going all the way across indicates its gonna fail, i have a BM 975 thats like that and has been for yrs now and it'll pass a spine test just fine, agree its probably not a good thing though lol.

and agree its not a good thing when they open up in your pocket either.
 
allenC said:
I have a friend who said the same thing...

I asked him this:
What firearms would you trust to defend your life and lives of your loved ones?

He said:
An AK-47, a Smith&Wesson .357 revolver, or a Glock 17.

I then said:
They all have springs, ya'know? :p

I can't repeat what he said after that! :D ;)



It depends upon which folders and which fixed-blades you're talking about...
The common household steak knife is a fixed-blade 100%.
But I'll bet that a Spyderco Manix is stronger than the average household steak knife!
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So you like single shotters and bolt actions?
 
First, I like lockers. Second, I also use slip joints, so the spine whackers are a mystery to me. The lock is a convenience during the proper use of a folder, not a necessity to be foolproof under any circumstances, certainly as safe as a fixed with no finger guard. So, maybe someone can explain the necessity of a blade lock for anything other than use as a weapon.:confused:

I prefer the frame or liner to the lock back because both can be an open back design that doesn't collect junk, but any are OK with me to use as a non-weapon knife. Just as important to me is that frames and liners do not require the tang to be machined away to an extent the blade base is weakened as in a back lock. Regards, ss.
 
straitshot said:
First, I like lockers. Second, I also use slip joints, so the spine whackers are a mystery to me. The lock is a convenience during the proper use of a folder, not a necessity to be foolproof under any circumstances, certainly as safe as a fixed with no finger guard. So, maybe someone can explain the necessity of a blade lock for anything other than use as a weapon.:confused:
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I have a question.

What do slipjoint people do when cutting quad-ply cardboard, or thick vinyl/linoleum?

The blade often will get hung up in the material, especially in cardboard as it begins to tear the outside layers instead of cut, and the only way to clear it is to restart the cut by jiggling the handle up and down, or in and out.

Alternately, what about making puncture cuts in heavy carpet? I had to do this the other day when I was marking out a section of carpet to cut in the middle of a larger piece. I had to stab through the carpet in the middle, something I would be very loathe to try with a blade that could slip closed with a lot of pressure behind the butt.

I would never dare do either of these tasks with a slipjoint.

Also, keep in mind that a slipping liner- or frame-lock actually has LESS reverse tension than a SAK's slipjoint or even a friction folder, so it can collapse MORE easily than a slipjoint on your fingers.

With sufficient finishing and lube, a malfunctioning lock (AXIS, liner, or what have you*) can actually swing shut on your fingers when held in a horizontal position if you overcome the initial tension with a nudge. This is why a malfunctioning lock is more dangerous than a slipjoint.

-j

*This happens less (or not at all) with lockbacks for the same reason that their action isn't as smooth -- rotational friction on the tang.
 
straitshot said:
First, I like lockers. Second, I also use slip joints, so the spine whackers are a mystery to me. The lock is a convenience during the proper use of a folder, not a necessity to be foolproof under any circumstances, certainly as safe as a fixed with no finger guard. So, maybe someone can explain the necessity of a blade lock for anything other than use as a weapon.:confused:.
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The answer is simple:
Accidents happen, and humans make mistakes.
A locking folder is more forgiving of those mistakes than a non-locking folder....but only if it's reliable and strong.

And since locking folders are just as easy to deploy and use as non-locking folders...the real question is: why NOT use a locking folder?
 
Try cutting a blister pack with a slip joint. especially when you want to put some pressure on the blade to help it along
 
Hmm, I had a cheap CRKT M-16 that I picked up from Walmart. After less than a day's worth of flicking the liner traveled almost all the way to the other side (nearly falling off the blade) and I just got really nervous over it and sold it to someone guaranteed to use her knife less hard than I would. What's the point of AutoLAWKS if there's no protection from the liner falling off the other side?

That said, I have played with the liner lock on a Spyderco Captain and I'd say that thing is SOLID. The compression lock seems to me like an almost fail-proof variation on the liner lock (yes, I know it uses completely different mechanics to ensure a lock).
 
carrot said:
Hmm, I had a cheap CRKT M-16 that I picked up from Walmart. After less than a day's worth of flicking the liner traveled almost all the way to the other side (nearly falling off the blade) and I just got really nervous over it and sold it to someone guaranteed to use her knife less hard than I would. What's the point of AutoLAWKS if there's no protection from the liner falling off the other side?
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Usually, the lockbar's thickness is thinner than that of the washer, so the only problem with excessive engagement (i.e. tang mate face is too short) is vertical blade play.

Note "usually".

That said, I have played with the liner lock on a Spyderco Captain and I'd say that thing is SOLID. The compression lock seems to me like an almost fail-proof variation on the liner lock (yes, I know it uses completely different mechanics to ensure a lock).
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Spyderco uses a particularly well-developed mate face cut -- it's radiused with the tangent a fraction of the way in from the disengagement point. The tang cut is fully tangential/perpendicular to the lockbar's mate face at static engagement. At the very end (at disengagement), the cut actually goes up again very slightly, making i

This makes it a LOT more difficult for the lockbar to slip off the tang with sustained pressure (although theoretically, with a strong enough impact, the lockbar will bow and "jump".)

CRKT uses a straight cut, which is why they prefer the roughened-up version -- to create friction so the lockbar isn't pushed off from the directed force.

If I understand things correctly, Spyderco's radiused cut is fairly difficult to execute correctly. A few other manufacturers use it -- Strider is one.

-j
 
I have had a couple of lockbacks fail on my hand a long time ago, but then I grew up and learned what a knife is for. Funny thing is that prior to the lockbacks I always carried a stockman and never had one close on my hand! Yes I like locks, but I am also falling back in love with slips as well, must be an age thing. Steven
 
Originally Posted by John T Wylie Jr
cut open those daily with my Case Whittler , never a problem.
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Same here John,exept with a Sak (Usually):thumbup:

Im like lock blades,and for certain uses they have their advantages,but my first knife was a slippie,and thats what I usually carry to this day.A non locking folder want fold unless your putting pressure against the back of the blade,and while some materials may pinch a blade and can cause a slippie to close,with care it's not and issue.

A lock blade is safer,but only if you don't relie on the lock!;)
 
I realize a lock facilitates a one-hand opener so it opens easily, and that in itself justifies a lock. I don't have a frame lock but carry a back lock daily and often use a frame lock while hunting. One thumb- opener I'm aware of that doesn't have a lock is the Spyderco UK, but I've not tried one. It's only that once a blade is open, I've have not relied on the locks to an extent that failure is likely, so spine whacking is not one of my considerations. :) Regards, ss.
 
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