A Safer Liner Lock?

P

phlatinum

Joined
Dec 8, 2001
Messages
156
I don't know much about the various types of locking mechanisms yet, so please bear with me. I just ordered a Mini AFCK, because I love the looks of it, the hole-in-the-blade opener, and the tip down carry feature. I realize that it is not considered a "rough use" folder, but Benchmade claims that this "modified" liner lock has a leg up on the competition, so to speak. Is it considerably safer/more reliable than other makers' liner locks, or is the advantage mostly theoretical? Does anyone (including custom makers) make a truly superior liner lock, as far as safety and reliability are concerned?
Thanks.
 
I'm no expert on liner locks but CRKT makes some knives with the LAWKs system.
It's hard to describe but it's like a safety switch for the liner lock. I don't see how it could possibly fail.

Good luck,
Allen.
 
Benchmade's twist on the liner lock is to put a radiused ramp on the blade tang. This has two effects, it compensates for more lock wear, and it creates a steeper angle on the ramp near the point of disengagement. This has been both good and bad in my experience. I had a 910 on which the lock would slip down off of the steep part of the ramp under steady closing pressure, but it would stop slipping when it reached the higher-angle portion of the ramp. So the bottom line was a lock that slipped and made me nervous, but never actually released under closing pressure. In general, I would say that they are no more or less reliable than any other good liner lock. Some of the most reliable liner locks that I have had experience with have been on my own 812HS and other Benchmades.

The other thing about the 812 is that it has stainless steel liners which makes for a stronger, and slightly more reliable lock in my opinion. Stainless liner locks wear less quickly, and are generally stronger in terms of the spring set you can put on them. I have had no problems with mine.
My 812HS is one of only three liner locks that I still carry. I really love the design as a small pocket utility knife. I still carry it quite frequently even though I have a couple of Axis locks in the same size range. I don't consider it "tactical". The lock is sufficiently reliable for a small utility knife. I carry a larger Axis lock or frame lock folder along with it as a defensive knife.
 
Allen,
Thanks for the heads up on the CRKT LAWKS. (Couldn't hardly even spell it yesterday!) The current models aren't quite my cup of tea, but the system sounds solid ... I'll keep an eye on CRKT. The Ryan 7 almost does it for me, except for the chunky blade style.

Steve,
I guess, if anything, you've made me feel even better about my little "combat knife" (grin). I will do battle with apples and marshmallow sticks without fear. Appreciate your take on the advantages of stainless liners, too. It is becoming obvious that I will need more knives. (I AM learning, no?) :D

Thanks again ... I love this place!
 
It is becoming obvious that I will need more knives.
Click to expand...

:D :D :D It all goes downhill from here...
 
Good choice. 812s has been on my pocket at least 3 days a week (in roatation LOL) for almost 5 years. Just sent it back to the factory to have a few things fixed but the knife performed flawlessly for years, the liner lock eventually became badly worn and the thing engages almost on the other side of the ramp. My only complaint is that from the factory the edge bevel is too thick. Once you thin it down the thing will perform like a razor. I own 4 mini afcks and two larger ones (all older style), any guess what my favorite style is?

JC
 
Originally posted by solid_soldier


:D :D :D It all goes downhill from here...
Click to expand...
:eek: That kind of topography seems familiar, somehow .....

Jameson ... FOUR of 'em, ya say, and a couple larger ones too ... hmmmmm .... you wouldn't happen to have 34 copies or so of "Catcher In The Rye" stashed about the house .... ??? :confused: :eek: :D
Wish that ups truck would move a little faster!!
 
Phlatinum,

No I only have one copy of catcher in the Rye. I have about 4 copies of "The Grapes of Wrath" and two of "In the Slick of the Cricket". About the knives.

The worst thing is I am a college student and I really dont need $600+ worth of the same knife in different sizes :rolleyes: . Worse off I used to have two Full Size M-2 Afcks which brought it up to 8 at one point. One good way to look at the whole knife thing is that they dont decrease in value very much. I caould sell each AFCK for exactly what I paid for it 5 years later (if it was still NIB). Much liek fishing tackle knives hold their value.

Look at it this way, if you ever want to get out of the knife community you will at least leave with a good chunk of change. And when you need $$$ the knives are always there to sell. Did I just say that :eek:

JC

P.S. Anyone want to trade a tnt for all of my afck's? :rolleyes: Worth a try.
 
Hi all. Back to the liner locks.

Jameson said something I've been wondering about. If the liner lock engages almost to the other side, isn't that a good thing? Considering that to unlock it would have to travel that much further back to the point of dis engagement. I had an Emerson Raven that was that way, it went so far to the other side that it was a b****h to unlock and close the blade.

What is the probrem with a liner going to the other side...
 
Originally posted by Quiet Priest
If the liner lock engages almost to the other side, isn't that a good thing? Considering that to unlock it would have to travel that much further back to the point of dis engagement. I had an Emerson Raven that was that way, it went so far to the other side that it was a b****h to unlock and close the blade.

What is the probrem with a liner going to the other side...
Click to expand...

Check out these threads: http://www.bladeforums.com/forums/showthread.php?s=&threadid=179976&highlight=lock and http://www.bladeforums.com/forums/showthread.php?s=&threadid=180681&highlight=lock

I have a BM 910 (M2-BT) Stryker. It has a Titanium liner lock...similar (I believe) to the AFCK. It was all I ever wanted in a locking mechanism...until I bought my first Sebenza. The Sebenza epitomized lock security. BM had a 750 (?) model that I bought and compared to the Sebenza when I was trying to decide which to keep. I went with the Sebenza. However, this is to in no way imply that the BM lock is "unsafe" or not a good design. I trust my BM fully...but IMO, the Sebenza represents the ultimate in security.

Check out CRK Sebenza at: http://www.chrisreeve.com/sebenza.html
 
Originally posted by Quiet Priest
Hi all. Back to the liner locks.

Jameson said something I've been wondering about. If the liner lock engages almost to the other side, isn't that a good thing? Considering that to unlock it would have to travel that much further back to the point of dis engagement. I had an Emerson Raven that was that way, it went so far to the other side that it was a b****h to unlock and close the blade.

What is the probrem with a liner going to the other side...
Click to expand...

Two answers:

1. The liner moving to the far side of the blade tang is the way a liner lock wears. Once the liner moves all the way to the farthest side, there's no more room to wear. When that happens, any further wear will cause play in the lock-up. This can be "fixed" by putting in a bigger stop pin (if you think about it, you'll see why), but there's some question as to whether or not a bigger stop pin will introduce a change in the geometry that will compromise reliability. In short: Once the liner reaches the far side, it's worn out, and some action or other must be taken, whether it's put in a new stop pin and hope for the best, or throw the knife out and buy a new one.

2. When the liner moves towards the far side, you're right, it does have farther to travel to unlock. However, think about the dynamics of this. If you put some kind of stress on the lock that causes the lock to start moving, you've already lost. It is that *first* movement that indicates failure, because the first movement is the hardest to obtain. Once the lock is moving, continued pressure will typically move the lock all the way to failure. I've been able to fail plenty of liner locks that locked up to the far right. In summary, how firm the lockup "feels", and how for over it is, is not an indication of how reliable the lockup is -- you must test it!. Provided the entire liner engages the blade tang, it is unclear to me that where the liner engages the tang has anything to do reliability. In fact, given the liner lock's sensitivity to tang/liner geometry, and the fact that sometimes liner locks that worked for a long time suddenly start failing, I tend to think that as the blade marches over to the right, every time the geometry changes a little, the lockup is unknown again.

Joe
 
Hey Rigor, thanks for the threads.

But I still don't get it. How is the liner moving over a bad lock thing?? I have gotten rid of the Raven and do own a Sebenza. But on budget knives, I'd rather the liner move over to the other side than stay on the edge by the point of disengaement.

Isn't that what really makes knives fail the spine whack test?

Forgive my ignorance on this but I really learn the most from asking those stupid questions others have but wont ask.
 
Quiet Priest,

Bet I'm more ignorant than you are. :D
I tend to embrace my stupidity ... each educational tidbit is the equivalent of a shiny gold nugget! Shiny is always good, too.

I really appreciate all you guys trying to explain the intimate inner workings of the liner lock. I'm following SOME of it, other parts, well ... wish I had a liner lock in front of me for personal inspection, but I don't own one yet. (How pathetic is that?!) Anyone know where we might find an exploded view of a liner lock, to help visualize just how they work, and wear? I'm not clear on which parts are engineered to wear out first. Is the liner replaceable?
Thanks.
 
Joe explained it correctly. What holds a liner lock on the ramp is its own almost insignificant spring pressure and the friction between the end of the lock bar and the ramp. Once that friction has been overcome, and the bar starts sliding across the ramp, it really doesn't matter how far it has to go. If the closing pressure is sustained, the lock will keep sliding.

That is the good thing about Benchmade's radiused tang ramps. Near the point of disengagement the ramp is almost perpendicular to the lock bar so the lock is almost mechanical. Almost.
 
Thank you Mr Talmadge, and everyone else.

I am begining to understand a little. I now understand how bladeplay will develop from the liner being worn enough to travel to the other side. I guess when I thought of failure the image I had was of the liner breaking so that the blade would the have no direction to go but fold over. Now I think that mabe the failure may be caused by the combination of blade play and weakening spring action of the liner.

I guess failure hadn't been clearly explained and I wonder how many others think of it as "stainless steel or titanium liner breaking from the stress of a 3" piece of metal and a little muscle??, metal is stronger than that!!" Other factors I've seen on some cheap knives is a tang (the part that connects to the liner) being convex in combination with a thin liner. Yes on my Benchmades the geometry is radiused and I see how that is an improvement. Wow, look at my new vocabulary!

As usual I am never disappointed by asking questions on this forum. I learn so much here even when just lurking, Hope I can benefit others from all this sometime.

Now, if only there were similar forums on Finances, getting laid, getting promotions at work, dealing with neighbors....
 
Also w/custom Ti liner (and frame) locks there appears to be at least two schools of thought. Some makers tend to spring the liner relatively "soft" and not too far beyond the point of tang contact (when disassembled)--perhaps as far as the opposite handle only (Carson, JW Smith, Terzuola, etc.).
The other school of thought heat treats the liner engagement surface (I know its Ti but it can be done although its not very deep) and springs the liner relatively "stiff" (Chris Reeves--not realy custom but started out that way, Bob Lum, Tom Mayo, etc).
The latter method tends to make a more reliable and wear resistant lock (in the long run) in my experience but one that may be more difficult to disengage.
 
Now, if only there were similar forums on Finances, getting laid, getting promotions at work, dealing with neighbors....
Click to expand...

Amen Mr. Priest
 
IMO, it's not so much who makes the lock but how well the geometry is in the lock mechanism.

I have had $500 customs that had locks that would close with pressure from the hand, a little firmer than a slip joint.

I have had $125 knives that were rock solid.

The problem comes from the fact that I also had the same model of the $125 knife with a junk lock.

So, in a nutshell I don't think it's so much who makes or the model the knife but how well the knife itself was made. Some may be good some may not be.

I have had over 100 knives some more than once and I have held and played with many many more. I have never seen a production company get a liner lock right every time. Likewise there are a few custom makers that I have never seen get a lock right.

Very few that I have seen have given me the impression that they can get it right every time, the ones who have are the dominating factors in my collection ;)

FWIW, these rules don't necessarily apply to frame locks. I have seen some frame locks that were junk but the vast majority of them are strong.

IMO, anyone who adds a secondary lock to their liner lock is just saying "hey, we know they fail if not done right and rather than do that we'll add this little thingy", sorry if that insults any fans of those brands but I think it's just a crutch.
 
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