Frame lock stronger then hidden liner lock?

nozh2002

nozh2002

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I am wondering why this is like generic consept?

Is it because frame lock is also "backed up" by hand?

If so this is not giving too much benefit really because forces leading lock to fail is much higher then hand can stand. It it is metal wise holding lock liner - I can understand that it really backed it up, but soft flesh wll not prevent lock to fail in case high pressure applied to the blade - I think thickness of liner plus this new button safety introduced by Strider as I understand may help (or high angle of lock like Microtech bar+spring), but sure not hand.

Hand may prevent frame lock flapping around, holding it in position, but I did not see any such locks on quality knives - they aways goes to lock position.

Only scenario I can imagine with frame lock better then liner is when lick got some trash and did not lock - then hand may in theory a bit push it in right position.

Thanks, Vassili.

Please, this is not an attack on any particular manufacturers, especially Strider - I just try to understand why it is presived as stronger lock.
 
I think the idea stems from two things:

a) the hand 'holds it closed'

b) Frame locks are almost always much thicker than liner locks.
 
Knife Outlet said:
B above is the salient point. The frame lock uses the full thickness of the handle.
Click to expand...

But the cutout thickness would also be a serious consideration from what I have read from STR's posts. Some of those really thick HD frame locks have .032" to .038" thickness in the cutouts, which doesn't seem very reassuring with titanium that thin. That is much thinner than most liner locks, and would concern me. Sal Glesser has posted that the cutout is the failure point in frame locks that he has destruction tested, if I recall. Of course, I'm no knife builder and don't own a framelock, but have handled a couple, I'm just going off of what I have read.

Mike
 
At least as importantly, when you're going to do something that stresses the knife, typically you squeeze the handle more tightly. With a framelock, squeezing the handle tightly will jam the lock into the blade tang more tightly -- to the point where on some framelocks, it can be hard to unlock after gripping tightly. On a liner lock, the hand never causes more positive engagement regarding the lockup. The best you can hope for is no engagement at all; at worst, the flesh of the hand interacts with the locking leaf and reduces the lockup integrity.

So, with the framelock, it's not just a matter of the hand helping to keep the lock closed, it's that the hand pushes the locking leaf into a tighter, more-secure position as more stress is put upon it.

I disagree that thickness of the locking leaf is the most important property regarding framelock vs liner lock. I agree it helps. But for me, it does not explain the difference in reliability between the two formats (i.e., even thick liner locks are less reliable than framelocks IME).
 
gunmike1 said:
But the cutout thickness would also be a serious consideration from what I have read from STR's posts. Some of those really thick HD frame locks have .032" to .038" thickness in the cutouts, which doesn't seem very reassuring with titanium that thin. That is much thinner than most liner locks, and would concern me. Sal Glesser has posted that the cutout is the failure point in frame locks that he has destruction tested, if I recall. Of course, I'm no knife builder and don't own a framelock, but have handled a couple, I'm just going off of what I have read.
Click to expand...

The thing is, strength isn't usually the issue. Reliability is, and the critical factors for reliability seem to live at the leaf/tang junction, not way back at the cutout.
 
Joe Talmadge said:
At least as importantly, when you're going to do something that stresses the knife, typically you squeeze the handle more tightly.
Click to expand...

Thank, it is good point - so hand help to lock it better, helping not to stand pressure at the point of possible failure but helping lock spring to lock it more secure.

Then it is matter of how strong is lock spring. From other hand with frame lock you may "manage" locking strength. If needed lock it tighter and if not needed keep it as it is.

I guess to it is possible to use this advantage with hidden lock - make some kind of button goes through scale near the blade which will allow tighten the lock way you described.

Thanks, Vassili.

Thickness of the lock is critical to certain point and some hidden locks - like Buck880 are pretty thick also it is more matter of design and some liner lock are thicker then frame locks.

Any other ideas?
 
Just remember a folder is a folder.It will never be as strong as a fixed blade regardless of the lock.:cool:
 
True, with ALL folders one should examine the lock carefully before using and every time. This spine whack fetish is basically nonsense,if you want 100% rigidity then opt for a fixed blade,full stop.
 
I'd also add that not all frame locks are created equally. I had one close on me, causing a cut. However, I trust CRK -- the geometry and lock bar/tang interface is very precise.
 
Joe Talmadge said:
The thing is, strength isn't usually the issue. Reliability is, and the critical factors for reliability seem to live at the leaf/tang junction, not way back at the cutout.
Click to expand...


I would agree, I was just responding to the thickness issue as it relates to strength issue, as that is a large part of what was brought up in the first post. The frame lock would definately seem to have an advantage in contact area with the tang (assuming it engages correctly), and like you pointed out, the fact that a death grip reinforces the engagement also would help reliability. While I haven't had any of my liner locks accidentally disengage (I haven't bought one in a couple years), I haven't tried any of the twisting cuts where I could see it being an issue. Also, from the reports I have read, these types of locks are the easiest to screw up on the manufacturing side, which could also add to the bad reliability reputation of liner locks. I personally like lockbacks, though the Ball Bearing and Axis lock knives I tried seemed very strong and reliable also.

Mike
 
willgoy said:
True, with ALL folders one should examine the lock carefully before using and every time. This spine whack fetish is basically nonsense,if you want 100% rigidity then opt for a fixed blade,full stop.
Click to expand...

Here's how I interpret this conversation:

Fred: I'm buying a new car. Looking for something that does 0-60 in 10 seconds or less.

Jim: Whoa there cowboy! Remember, a Formula 1 racecar will be faster than a regular car.

Jack: Yeah, this thing about a regular car doing 0-60 in 10 seconds is nonsense. You want that kind of speed, get a Formula 1 racecar.

Fred: Wait a minute. I'm not asking for Formula 1 racecar. I'm asking for a level of performance that many many regular cars can easily reach.


In looking at lock reliability issues, I don't think I've ever seen the term "100% rigidity" used. No one is mistaking a folder for a fixed blade. We're saying there's a basic, reasonable level of performance for a folder that we want. And since many folders easily pass all tests, there's no issue at all, and no reason to run around telling people to buy fixed blades just because they ask for some basic easily-achieved level of lock reliability.
 
Now I admit I'm no framelock expert... but
what about the possibility of a framelock unlocking
do to certain wrist torques? Being that the hand is on the
lock itself, couldn't the lock open if you twist to the right if
the lock is on the right? Just curious to see if this has
happened to anyone.
 
Buck882 is possible to fold with lock locked without too much pressure or by slightly hitting it. And I can blame only liner thickness - it allows lock to bend out of right position. So thickness really matter - lock should not be too thin as it is on that model. And in that case I belive it does not really matter is it frame lock or hidden lock.

Thanks, Vassili.
 
Vassili, one of the best liner locks I've tested was a gentleman's folder with an incredibly thin titanium linerlock. The maker and I put so much stress on the blade that the liner flexed at an outrageous angle. But, we were never able to get that liner to pop off. That's one of many cases that has convinced me that if you get the lock/tang geometry right, thickness or thinness of the liner does not matter. A thicker liner does nothing but give the maker a margin of error on the lock/tang geometry -- it allows him to make small mistakes on the geometry and still be okay. But if liner thickness were the prime determining factor, there wouldn't be so many rock solid thin liner locks, or so many thicker liners that fail. Thick liner = more margin of error, but lock/tang geometry = reliability or not.

msiley, no doubt framelocks can be susceptible to counterclockwise torque for the reason you mention (assuming a righty framelock). My theory as to why we don't see more of this in real life: by the time you're torquing hard, you've probably already held the knife very firmly so the lockup is already reinforced significantly.

gunmike1: gotcha, agreed!
 
Joe Talmadge said:
Fred: I'm buying a new car. Looking for something that does 0-60 in 10 seconds or less.
Jim: Whoa there cowboy! Remember, a Formula 1 racecar will be faster than a regular car.
Click to expand...

This is again in theory, toughness of fixed blade depends on tang construction and thickness and length and steel and HT. It is not like any fixed blade is tougher then any folder. So it is not really Formula I. I also may say that this difference is hypothetical and any fixed blade will not stand against just regular pry-bar in this kind of use cases, but may be bit better then good folder.

However this is matter of different thread.

Thanks, Vassili.
 
Joe Talmadge said:
Here's how I interpret this conversation:

Fred: I'm buying a new car. Looking for something that does 0-60 in 10 seconds or less.

Jim: Whoa there cowboy! Remember, a Formula 1 racecar will be faster than a regular car.

Jack: Yeah, this thing about a regular car doing 0-60 in 10 seconds is nonsense. You want that kind of speed, get a Formula 1 racecar.

Fred: Wait a minute. I'm not asking for Formula 1 racecar. I'm asking for a level of performance that many many regular cars can easily reach.


In looking at lock reliability issues, I don't think I've ever seen the term "100% rigidity" used. No one is mistaking a folder for a fixed blade. We're saying there's a basic, reasonable level of performance for a folder that we want. And since many folders easily pass all tests, there's no issue at all, and no reason to run around telling people to buy fixed blades just because they ask for some basic easily-achieved level of lock reliability.
Click to expand...

Maybe not, and incidentally, the vast majority of my knives are NOT fixed-blade.It's just that I WONDER why people are so obsessed with whacking folders to the extreme? Back to my point again, if you really INSIST on putting a knife under the cosh then opt for fixed. I feel sure that most of my Bucks, Spyders, Case copperlock, Mcusta, Kizlyar and even some Chinese ones can stand general use with no worries. Not so with a couple of Bökers or Herbertz I have, they have very dubious locks :eek:

Just exactly what extreme conditions would one have in mind to test these folders? Practically I mean? It all begins to sound like the medieval theologians arguing about angels on pin-heads:D

Just steer clear from slip-joints;)
 
The thickness difference has only a little advantage for the frame lock based on the way most of them are built. The real advantage is as Joe already described.

Most are built just like this here so even though you have all that mass of lock to look at you can see how much of it on most knives of this type is actually coming into contact with the blade. Some have very little surface area in contact with the blade. I've seen several models that do better than this one pictured. Surprizingly they are not anywhere near the cost though. Some like the Kershaw Storms and some other Kershaw models I've examined have quite a bit of surface to surface contact with absolutely no blade rock at all. Mostly this is just a philosophy difference in how you should build one I think but many times some just have a bit more contact surface area than others. As with anything mass produced there are variances. Everyone builds them this way though as it is the 'standard' or 'correct' way to make the contact so the blade does not rock.

The Sebenzas I have seen or owned that I have done this same test of first taking the knives apart and then looking at them like in the picture where they are exactly positioned as they are when opened so I can hold them up to direct sunlight allows very little light to come through like this example. This example here is very typical of the amount of contact you can expect on any typical liner or frame lock as far as the portion of the lock that actually is reponsible for stopping the blade from closing though. My point is I've seen better. I hope you can see this. I had to resize it to load it. I have another if this one doesn't show up well enough for you to make out that you can actually see the screen of my back window looking under the lock. This is the same position the blade is in when fully opened against the stop and the lock is engaged behind the blade.

STR
 
I personally prefer framelocks and if all consideration are made: good design, made to the exacting design and all factors considered, failure should be minimized. Remember that nothing is perfect, you can only do so much. Tolerances can be kept to a minimum. I think failures could also be due to human ineptitude. CRK makes the best framelock !!
 
This post pertains to the twisting of a liner lock. This past year i was bowfishing in louisiana for alligators. the first 9 footer we pulled in the boat my buddy went to finish it off with a nice prouduction Emerson liner lock. He stuck the croc in the back of the neck trying to cut his spine and luckily the knife was in deep enough that when he put some torque on the blade the knife shut and only cut one of his fingers. I promptly handed him a fixed bladed knife and he finished the job. Now you can't expect a folder to work as a fixed blade like the gentlemen posted and i am not saying anything bad about folders i was just replying to the gentlemens question about folders shutting when twisted or torqued. I like folders and have a large collection of them they have there place. But anytime i think i may really need a knife i carry a fixed blade you never know what your gonna get into. I think the meat of his hand must have pushed on the liner and caused it to shut
 
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