Lockback Stronger Than Liner Lock, etc.

[hardheart]

If you are saying pound for pound or mm for mm, yes, you are correct

more like pound for two pounds, as the frn lockback was less than half the weight. The lighter and thinner knife was stronger, because the design of the liner lock is not as strong. This is a very basic thing, the lock and spring are the same piece on the liner lock, and the distribution of forces is different from the lockback.

I did not say all liner locks are inferior to all lockbacks, but I will say that I can't find anything suggesting that any liner lock is superior to any lock back of the same build quality. There are plenty of reasons for people to like liner locks. Being stronger than another lock isn't going to be one of those reasons. And the frame lock is in the same boat. Again, the locks are strong enough, but they are not 'bragging rights' kinds of locks the way someone migh talk about how wear resistant their S110V blade is, or how aesthetically pleasing their presentation grade ironwood scales are.

 

[res1cue]

Imo the lockback is the strongest locking mechanism beside framelock. Normally the lockback has a stronger backspring than the liner ever could be. A liner lock doesnt show this safety to me like any backlock.

Kind regards

Now keep in mind that a stronger backspring is a good prevention against accidental disengagement. It doesn't actually provide strength. Two different animals

 

[res1cue]

I did not say all liner locks are inferior to all lockbacks

I know, that was more directed at the OP

I can't find anything suggesting that any liner lock is superior to any lock back of the same build quality.

of course not

There are plenty of reasons for people to like liner locks. Being stronger than another lock isn't going to be one of those reasons.

Completely agree. Just saying to write off all liner locks as weak would be a mistake. I personally do not like liner locks, but I have a healthy respect for my Emersons, my Sere 2K, and my ZT 0200

 

[Humppa]

What I wanted to say; a backlock is safer than a liner lock (depends on the comparison - you can´t compare a thin metalsheet to a strong backspring because there´s much more material which can hold on the blade in its place) and stronger anyhow. If you would compare a Buck 110 to any linerlock modell you can see, that you would have a framelock like Sebenza because of the materialthickness.

@res1cue: So you´re right, two different animals like comparing cats and dogs...

My 2 cent

Kind regards

 

[Chris "Anagarika"]

Another aspect to think about is the slab that support the pivot. On liner lock or frame lock, one side will have less metal supporting the pivot because it's cut to make the lock.

On lock back (and axis or similar type lock), the two slabs supporting the pivot are equal, so the pressure distribution is better.

 

[dhaines]

Here is my way of describing when a liner lock or frame lock will fail...

This is my hypothesis...I think the lock will fail depending on the angle the thing is cut at on the lock bar and the blade not the strength of the lock itself.

this is how I get there
Force = Mass x Acceleration.

In the case of free falling objects Acceleration is equal to gravity, however, on an inclined plan the presence of an incline prevents the object from falling straight down. Instead it must accelerate with some component of gravity.

Now recall that perpendicular forces of action on an Incline plane are calculated by Sin theta and that perpendicular forces ( the normal force) is calculated by Cos theta (Theta is the angle an object is on a plane or the angle a blade is on a lockbar)

Hence the total force parallel to the object described by variable g = force on blade and mu = the coefficient of friction between the lockbar and the blade would be

Force Y up and down = (g sin theta)mu
Force X Left and right = (g cos theta)mu

You have to multiply g sin theta times the coefficient of friction between the lock and the lockbar to get the exact force of pressure from the blade this is when the lock will fail if the lock bar and or liner lock is built to withstand forces stronger then g sin theta. If they are not built stronger to withstand the forces of g sin theta they will fail as at the weakest part of the lock.

Thoughts?

 

[Maddogg774]

That is given if all the material, finish and sizes of subjects are equal. Every single knife, even ones of the exact same make and model are different. They may have a similar range of failure. Btw your "equation" is similar to bridge failure formula.

 

[jbmonkey]

i'm no knifemaker or engineer or physics major, but when i see an article written by Mr. Bernard Levine about Mr. Walker and his liner lock i tend to believe it and here is what he said about a liner locks strength compared to a backlock.......

"STRONG AND SECURE

As it worked out, Mike had not anticipated just how strong

his new lock would be. About 1984 I helped to run side-by-side

destruction tests of all the types of locking folders available

at that time. Each test involved securing the handle of the knife

without blocking the movement of its blade or spring; then

sliding a one-foot pipe over the open blade (which was oriented

edge downward), to serve as a lever-arm; and finally hanging

weights from the free end of the pipe until the lock failed.

Name-brand conventional factory lockbacks failed at between

5 and 7 foot pounds (except for one that failed with just the

weight of the pipe). A Paul button-lock knife proved to be more

than twice as strong as the best of the conventional lockbacks.

But a Walker Linerlock was nearly four times as strong as the

lockbacks. What's more, when Walker's Locker did finally fail, it

failed in the open position. Instead of closing suddenly upon

failure, as all the other knives did, it seized up and became a

"fixed" blade. "

"Mike is flattered that so many makers and manufacturers use

his invention, though he is disappointed that most of them fail

to grasp all the subtleties of the Linerlock mechanism. Because

of this, most of their knives lack the strength and smoothness of

Walker's own. "

here is the full read link......

http://www.knife-expert.com/liners.txt

i think this says it all.

 

[ron_m80]

There are a couple of different forces at play in the two different locks, so to simply say the lockback is stronger just because it has obvious width doesn't fully analyze the ingenious use of material strength in a liner lock.

As has been said, there are other factors and this blanket statement can't hold up to close analysis.

 

[Barrabas]

Great question.. I have also mulled it over time and again...kind of helped the light come on for me when I realized the best and most robust folders made by any Maker/Manufacturer all have one thing in common..they fold. .
That being said, the folders that give the best represenation to me of their respective lock's strength/integrity, I judge by Blade play after normal to moderate use (more of a concern to me on liner locks/Frame locks because the blade rests on the lock without the lateral support the lockback has when resting in it's indent, and if there is play..well that means that by virtue of the play, there is movement on the lock) , but perhaps the biggest factor to me is the amount of surface contact with whatever parts of the mechansim actually engage or support the lock.
Like said earlier, if I am in a situation where using a folder would make me question whether or not the lock would fail, I prefer to use another tool, or fixed blade in that application for a few reasons..1 ) I like my folders, and hate the thought of potential warranty work if I screw it up. 2) Even though a lock "can take it", how long can it take it before I am back to 1.. and 3) I like my fingers, and prefer they remain attached to my body without surgery.

If under normal use, a lock becomes suspect to me..and I don't have enough $ in it to pursue a warranty..I ditch it, or banish it to the drawer.
Summary: Have not had a liner lock that I trust yet to prolonged hard use, but I am sure there is one..so for me I like Frame locks, Lock backs and ARC locks.
Frames top it off simply because they are a great compromise between lock strength/one handed close, and are freaking cool...But I have had both Frames and Lockbacks in the past that have been banished..depends on the manufacturer and/or how much I abuse them.

Another pro for Lockbacks though, is they have been around a good while, and a well made one's lock is arguably less of a pain to maintain overall than some Frame locks, ARC, Compression etc.

 

[hardheart]

As has been said, there are other factors and this blanket statement can't hold up to close analysis.

but the close analysis with hundreds of knives of different locks being tested has been done, and is where the statement comes from. The weakest, least reliable, most poorly built lockback is not as strong as a properly executed linerlock, I don't think anyone could hope to argue differently. Lockbacks of similar materials and build quality are stronger than linerlocks, including the best linerlocks against the best lockbacks.

I don't see the resistance to results of standardized, repeated testing by some of the most reliable and respected names in the industry. Linerlocks work very well, they do not do some things as well as other locks. These things are likely even irrelevant to most folding knife use. The results of engineering and testing still remain the same.

 

[ron_m80]

but the close analysis with hundreds of knives of different locks being tested has been done, .............I don't see the resistance to results of standardized, repeated testing by some of the most reliable and respected names in the industry. Linerlocks work very well, they do not do some things as well as other locks. These things are likely even irrelevant to most folding knife use. The results of engineering and testing still remain the same.

What resistance. Jesus Double H again?... I wasn't trying to tell the man what to think, just that his approach was not accurate.

 

[stabman]

The cheap, shoddy lock is weaker than the properly made, well executed lock.

 

[Chris "Anagarika"]

The sticky thread of Tips and Tricks at STR's subforum has some good insights of what makes a good liner lock.

 

[anthony cheeseboro]

The bottom line is that the type of locks manufacturers use reflect popularity or consumer demand, not strength. The fact liner locks can be flipped open quickly have more to do with their popularity than their strength.