importance of locks

[Gryffin]

Security of a lock is directly related to the strength if you are using it in an extreme situation.

Here, I disagree. Even a lock that's strong (statically) can fail, whether it's by torquing the lock like Cliff does, or by whatever weirdness seems to happen during a light spine whack. That was my point, in fact.

I have not read the thread in question, nor do I need to. Beating a knife until it breaks then calling it defective is not something I'm in favor of.

Neither am I.

I have had a liner lock fail on me in just the real world, non abuse type scenario people think the spine whack fails to support.

I wasn't talking about beating a lock into submission; failure in that case isn't a huge surprise. I was talking about how otherwise strong lock seem to fail under conditions far less brutal, such as a light spine whack, or even an accident bump against a table or desk.

If a company advertises (or insinuates) their lock is bullet proof than people have every right to prove those claims, to what extreme is up to debate.

Good point. In fact, I think that's part of the problem; manufacturers have set expectations pretty high, implying that their locks are "bulletproof" when the reality is that any lock can fail.

(A) I've never seen a bonified failure of an Axis lock

Yeah, the Axis lock seems to avoid the problems of other locks, and is remarkably self-correcting. I've never heard of a failure either.

(B) Some locks fail more than others, and even though one model knife is good, the next may not be.

Definitely true. And as you noticed, even expensive, hand-fitted customs aren't immune, much less mass produced factory knives.

(C) Different locks for different uses.

Agreed. While I've been known to defend liner locks for everyday use, on a true hard-use knife, I'd prefer something more substantial and statistically reliable.

 

[STR]

In fact, I think that's part of the problem; manufacturers have set expectations pretty high, implying that their locks are "bulletproof" when the reality is that any lock can fail.

This is a very good point. It does seem to come back to haunt some companies when their product is promoted as such a tough knife. Particularly those that promote them with a DVD as Cliff has pointed out many times.

Even still most of that is cleared up as soon as you read the warranty. Many of the companies are very good at trying to do right by their customers but beating up a knife by whacking it repeatedly until it fails and then sending it in for a warranty repair is a no brainer. Just read the paste I put in the post with the samplings of warranty info. It is cut and dry and clear as can be.

 

[Joe Talmadge]

:thumbup:

Finally a voice of reason. Wha tis hte problem with testing both the strenght and security of a lock. I for one would like to see Cliff (or anyone else willing to step up) to test both.

run, Cliff tests both security (reliability) and strength every time, from what I can tell. So do a number of others. While it does appear some people in this thread might be using the term "strength" when they meant "reliability", Cliff isn't one of them.

 

[ZippyDan]

anyone know what kind of lock the sog tf-2 has?

 

[STR]

Strength is the ability to endure which the knives in question did not show for the spine whacks given them from what I read in the tests done on them. Do we know how many whacks? Well, I guess one knife was stronger than the other two actually but even it was made to defeat by the user. So how many whacks there?

At that point of defeating the lock security or reliability went out the window when the lock failed to keep the blade open for the user so it isn't even relevant anymore to this discussion for the three knives in question. At least in my mind which is why I was talking about strength.

At the point of failure all trust in the lock was lost after that by its owner regardless of the cause or reasoning behind the failure from what I can tell and that is what I think of when I think of security: trust. If the lock was still trusted it wouldn't be on it's way back to the manufacturer or be in question so, strength is the real question everyone is waiting to hear about I think. I guess the real question is how much strength is reasonable in this class of folder?

Is it reasonable to whack a locking folder of this type until it is made to fail? Or is it reasonable to give up after 1 successful whack where the lock did its job? Or after 3, 5, 10, 500 whacks?? When does the test end before a user is convinced it is a reliable and secure lock? Anyone? Oh I get it: not until you can blow the trust and/or security and/or reliability of the lock out the window and convince yourself it is now unreliable and insecure because it failed. So what if you had to ding it up and whack it 6 times to get there on one knife and 3 on the other right? You see the dilema?

I suggest it is not reasonable to continue whacking it if it has succeeded in keeping the blade opened and locked after a good tap on the spine similar to any real world event that could occur during the uses it was made to perform. Obviously the parameters for the test are going to be more demanding for anything MBC rated, and lesser for others of less need for a lock so strong right? But to keep whacking and whacking til failure? Well, that is just gross abuse of an otherwise fine knife. Another reason I have a problem with spine whacks is due to this big question: where do we draw the line and conclude it is a fine reliable lock up?

 

[Merek]

Oh boy. Here we go again. Joe, if a lock isn't a safety device what would you call it?

Like anything, there is a right and wrong way to use a knife. .... What in the world makes anyone think that just because a manufacturer put a lock on a folder makes it so you no longer have to use the knife with good old common sense is beyond me to comprehend....just because you have and carry a locking folder regardless of the type of lock, doesn't mean you can just let go and forget all safety protocol for when you use the knife. ..

Thank you STR! Through all this thread and all the similar ones, this is my thought exactly. The only 'folding' failure I ever had was with a common non-locking slip joint being used injudiciously as a drill. My stupid and my scar. I will always trust the locks of my Buck 110s even though they are frequently used to hammer, pry, wedge, split and twist in conditions too numerous to relate and despite the fact my knives are rarely cleaned and full of crud, grit and grunge I have yet to have a 110 lock seem as if failure was an option.
While this is apparently a very important issue to many people ( like the self-defense knife) it makes me wonder what the point really is. The IS a right way and an unsafe way... if you think scars are cool, carry on doing what you can to force the lock.... I am sure there are those 'life and death' perhaps once in a lifetime scenarios that can be pointed to....like self-defense, perhaps. Once. Perhaps. More than once? Hmmm....

 

[DGG]

Here is a tread about Syderco locks failing.

http://www.bladeforums.com/forums/showthread.php?t=366883

 

[Cliff Stamp]

Can you name me a few production folders that have sharpened clips/spines/double edges for back-cutting?

Isn't the Chinook designed to be able to take this in martial applications? People have commented that Keatings instructors teach this in use of the knife and he designed it. Ralph makes dagger folding blades, the Maxx has such profiles.

Cliff it sounds to me like you want to make the locking folder regardless of type, a fixed blade in strength ...

No, I would just like to see the abilities of the lock consistent with the abilities of the blade. As noted I use knives that don't even have locks.

[spine whack lock releases]

In fact it is probably par for the course on all of them and the Manix too.

Nice of you to say that about Spyderco's products. I would wonder how you would react to another maker saying this about a problem with your blades which is in contention to your viewpoint.

You know as well as I do that there is no 100% secure lock made.

This is no unbreakable fixed blade either. It isn't that you can cause the lock to release or break, it is what it takes to do so which is the issue.

I don't recall saying that the better locking folders couldn't be used beyond the limits of a slip joint.

Yes you did :

"I know many ranch hands, construction workers and farmers that have never had a locking folder in their pocket and they don't limit the use of their slip joint knives at all."

Of course they limit them as there are things you don't do with slip joints that you can do with knives with solid locks, the better the lock the more you can do.

No one is claiming a slip joint is a tactical defense weapon.

But people are claiming lots of locking folders are just that.

Last tactical knife I bought said in big letters in the paper work that came with it that using it as a pry bar would constitute abuse and would void the warranty.

Prying isn't a problem for locks, even liner locks. Strength is rarely the issue. This is only really a concern on FRN knives where micro screws can shear handle slabs.

What tactical knife are you using where the manufacturer feels otherwise and has that in writing or on their web site Cliff?

Strider has openly promoted prying with thier folders, I would hope ER accepts it as normal use as otherwise a 1/4" sabre ground blade is kind of pointless. There are lots of very thick blades on folders now, if they are not meant to be used for prying and such then that is the wrong blade profile.

As for stabbing, in general when people do stabbing and thrusting tests and talk about stabbing with a knife they mean something more difficult than a tomato, which isn't a stab but a push. In regards to fighting knives, thrusts are likely to encouter much higher spine loads than pushing a knife through a tomato.

-Cliff

 

[STR]

Speak for yourself there Cliff. I didn't say what you are insinuating by putting words in my mouth. I don't want to beat a dead horse or derail this thread by going farther than that on this though. The topic isn't about that.

And as for your saying I am putting down my favorite knife company or one of the best guys in this business of knife making or his products; I resent that. When I say it is par for the course it means par for the course for someone taking the knife beyond normal limits of what is acceptable use of the cutting tool and the lock. You conveiently left out the part of my statement that says it is a folder with a lock and most any can be made to fail when tweaked the right way.

Based on the warranty in their catalog this spine whacking test is clearly into the abuse arena. If the blades show any signs of denting or dings it is an open and shut case. Warranty void. How much clearer can a statement be. "Use of our knives for any purpose other than cutting is considered abuse." No offense to High the owner of these knives but by his own admission he voided the warranty when he used the three of them and two other brands for purposes of testing by spine whacking them. If SAL covers even one of them he should count himself lucky IMO.

If on the other hand the knives failed the spine tap (not whack) that duplicates a real world event happening and there is no tell tale signs of severe blows to the spine, yes I would agree with you that the lock is probably needing redone or the knife replaced. I'm not disputing a lot of what is claimed by those that differ in view to this than myself. I just draw the line in a different place more based on company expectations than the rest of you apparently. If you guys had your way no company could survive the financial onslaught of returns based on what you expect or want out of these knives.

 

[Gryffin]

Isn't the Chinook designed to be able to take this in martial applications? People have commented that Keatings instructors teach this in use of the knife and he designed it. Ralph makes dagger folding blades, the Maxx has such profiles.

I don't have a Chinook, but I'm signed up for an upcoming passaround for one. From the photos I've seen, the spine is full thickness, although I suppose the trailing point could be of some use on a back cut. But the spine isn't sharpened, definitely.

As for the Maxx, even the dagger-ground model doens't have a sharpened spine. Good thing, too, since like virtually folders (balisongs excepted), the spine extends outside of the handle when closed. I can't imagine having an exposed sharp edge in your pocket could be considered a good idea!

It's driving me nuts, I *know* I've seen photos of a couple folding double-edge knives (customs, probably), but can't remember where I saw 'em...

 

[STR]

Most double edged knives conceal in the handles when closed to prevent cutting you. Most are illegal in all but a few states too as I recall.

 

[Cliff Stamp]

Based on the warranty in their catalog this spine whacking test is clearly into the abuse arena.

Here is part of the description from the Spyderco Website :

"The folder has a modified-Bowie-shaped blade and an MBC rated locking system so the knife could be used for cutting as well as passing or blocking."

Note the use of the blade goes beyond just cutting. If this knife fails a spine whack, and this is the expected behavior then the above needs to be changed as it is deceptive.

To be clear, I don't think this is the case because that isn't the expected behavior of the lock based on what I have seen with that knife and lockbacks in general.

As for "spine tap" tests, these are a horribly low stand, a slip joint passes them easily, a lock should have a higher standard. Not everyone rates spine whacks as abusive, and it only takes *ONE* maker to say otherwise and this makes everyone else admit to inferiority in that regard.

And again, consider simply hard thrust or stabbing, is this abuse to a tactical/fighting folder? It can easily spine load a blade heavily generating both a large impact as well as static load. If spine whacks are abuse then so are thrusts/stabs.

-Cliff

 

[bquinlan]

It's driving me nuts, I *know* I've seen photos of a couple folding double-edge knives (customs, probably), but can't remember where I saw 'em...

I'm sure there are a bunch of them, but the only one that comes immediately to mind is the Bob Dozier Thorn. Ka-Bar's version does not come with the back edge sharpened, but it can be. The frame does cover both blade edges when closed.

--Bob Q

 

[STR]

No Cliff. A good spine tap is sufficient IMO. Joe pointed out that if you imagine a knife stuck in something after a thrust and you pulled it out and in the rigor of a fight or from fast movement you snapped it back by pulling it hard out of whatever it was stuck in and gave it a good tap on something behind you how that is a 'real world' situation. A good tap or smack to the tip or spine of the blade one time not a repeat the same way over again and again.

The problem I see here in this logic is the definitive difference between whacking an open blade in a specific way with precision on a board mounted to a table after you dawn protective gloves, safety glasses or a special grip and a special stance' and a real life tap, smack or block on the spine one time or two from different angles on different places along the spine in a real life scenario. In my mind there is a big difference. Dropping it or loosing it and having it fly out of your hand or knocked out by an opponent and hitting the hardwood floor or a sheetrocked wall is a more real life test than the spine whack.

Again. How many whacks before it is beyond what the folders lock is supposed to be able to endure?

 

[WadeF]

Can someone elaborate on how strong a balisong lock really is? I've seen a lot of people be quick to state the balisong has the strongest lock, but they never explain why that is. When I look at my benchmade I don't put a lot of trust in it's strength compared to one of my BM axis locks. There is only 1 small stop pin that prevents the handle from continuing to pivot. What happens if that pin gets sheared? There isn't that much material there compared to the material on an axis lock. Even the latch is only secured by a small metal pin, but I wouldn't expect lock failure there, I'd expect failure from the pin on the tang off the blade, if you can even call it a tang.

 

[Gryffin]

I'm sure there are a bunch of them, but the only one that comes immediately to mind is the Bob Dozier Thorn. Ka-Bar's version does not come with the back edge sharpened, but it can be. The frame does cover both blade edges when closed.

Ah HAH!! That's one I was thinking of. Oddball design, centered pivot, that's how it keeps the blade enclosed. Since I wrote that, I remembered that the Gerber Combat and Covert work the same way, but also aren't sharpened both sides.

Thanks!

 

[Gryffin]

Can someone elaborate on how strong a balisong lock really is? I've seen a lot of people be quick to state the balisong has the strongest lock, but they never explain why that is.

Look at it this way: most folding knives lock the blade by moving something in the way of the blade:

• liner lock: a tab bent on the liner that blocks the rear of the blade tang;
• framelock: a tab bent in the frame that blocks the rear of the blade tang;
• lockback: a "hook" on the lock bar that engages a notch on the tang;
• button lock, a pin that engages a slot in the tang;
• REKAT Rolling Lock: rotating bar that engages a notch in the blade tang;
• Axis lock, the Axis bar that wedges between the blade tang;
• Spyderco Compression lock: a tab bent in the liner or frame that wedges between the blade tang and stop pin.

In each case, the locking member travels only a short distance, so accidental contact can, theoretically at least, disengage the lock.

Other than deliberate disengagement of the locking member, the only way for the lock to fail is material failure: buckling a liner, shearing a pin, tearing out a hole in the liner or scales. Note, though, that this applies to fixed blade knives, too; a blade or handle could break under load.

On a balisong, the handles are the lock. Yes, the stop pin could shear -- material failure, as above -- like any other locking mechanism, or even a fixed blade; but so long as you hold the handles together, there's no mechanical way for the lock to disengage.

A balisong isn't as strong as a fiixed blade, of course; it would take much less stress to shear the stop pin or pivot pins than to break any decently-made fixed blade. And on most of the balis I've seen, it would take much less stress to shear those pins than to shear an Axis bar or tear it out of the liners.

So, going back to what I wrote above, it's not the strongest design, but among folding knives, arguably the most secure.

 

[Joe Talmadge]

Although no one has tested it, in theory at least the lock on AR Niemi's Megaladon should be stronger than any balisong's: Shearing through the pins on the balisong would seem to be a walk in the park compared to shearing a big hardened S30V locking lug through the 1/8" hardened S30V frame. Course, AR isn't making these anymore; I just love to tweak the balisong guys

 

[Gryffin]

Sounds like the b'fly knife guys who say that balis are the strongest folders need to go read my posts here. They're confusing strong locks with secure locks!

 

[Danzz]

Sounds like the b'fly knife guys who say that balis are the strongest folders need to go read my posts here. They're confusing strong locks with secure locks!

No offense, but I never made that claim. In a good bali, though, such as the BM-42 or Spyderfly, the tang pin is steel ~60% embedded in a steel blade. I've never heard of a balisong failing due to the pin shearing- IMO, the pin is so short that you couldn't put enough torque on it to snap it off without first breaking the handles or the blade. And you'd have to shear the pin in two places at once- where it extends from BOTH sides of the blade, and even if it did happen, as long as you were gripping the handles tight the blade still wouldn't close on your fingers.
So not doubtlessly the strongest folder, but a solid contender.