Spine whack test?

[Mikel_24]

You're right. Absolutely no good reason to own a locking folder.

Regards,
3G

Uh... re-reading my first post I think I was somewhat harsh. A lock gives you a bit of peace of mind and might be a few ocasions when a lock would be wellcome. A blade with some sort of gut hook on the spine (ala the serrated blade on the Leatherman Charge) might requiere a lock...
Mikel

 

[3Guardsmen]

Then you will never know if the lock is truely reliable or not.
And if you don't care if the lock is reliable, then why not just use a slip-joint folder?

Yes he will, no lock is completely reliable.

You're absolutely right, so why should anyone even bother to try to find out if their knife's lock is even semi reliable? I mean, the safety mechanisms on guns aren't completely reliable, so why even bother putting your gun on 'safe'? Heck, child-proof caps on medicine bottles aren't completely 'child-proof,' so why use 'em?

Regards,
3G

 

[allenC]

I stand by my earlier statement that if a lock fails, it is more likely the fault of the user than the manufacturer. If you want to whack a knife into a desk, get a large fixed blade. I cut things every day and in 41 years of using knives, I still have all my fingers, and I've never had a lock fail. Use folders only for cutting. If you need to stab or chop, get out the fixed blade.

I personally would not buy any locking folder from any manufacturer or maker who told me that the lock would work just fine so long as I never hit the spine of the blade on anything.
That's not a locking folder, that's just a needlessly complicated slip-joint.

 

[3Guardsmen]

A blade with some sort of gut hook on the spine (ala the serrated blade on the Leatherman Charge) might requiere a lock...
Mikel

Um, I've got some bad news for you on that one, Mikel_24. In my experience with Leatherman Charges, the 'lock' on the knife blades is next to useless. I'm not talking anywhere near a 'spine-whack' here, I'm saying those liner-locks will not be forgiving of even a slight bump on a sofa! Be very careful!

Regards,
3G

 

[3Guardsmen]

I personally would not buy any locking folder from any manufacturer or maker who told me that the lock would work just fine so long as I never hit the spine of the blade on anything.
That's not a locking folder, that's just a needlessly complicated slip-joint.

Amen!:thumbup:

 

[pvicenzi]

Heck, child-proof caps on medicine bottles aren't completely 'child-proof,' so why use 'em?

Regards,
3G

I agree, those things exist just to satify lawyers.

 

[the lone gunman]

This probably rings true with many folks here.





OT, but the idea that this is abuse always drove me crazy. Why is it that revolver companies can make a cylinder that can withstand 20,000-40,000 psi and more without exploding in your hand, yet cannot be made so that it can be flipped closed without damaging the gun?

I think that flipping the cylinder closed is not so much that you will damage the mechanics of the gun, Its just that doing so is what causes worn blueing around the cylinder stops . Something I always note if buying a used revolver.

 

[allenC]

I agree, those things exist just to satify lawyers.

So Pvicenzi, would you buy a locking folder from a maker who told you "The lock works great IF you don't accidentally hit the spine of the blade on anything"?

 

[pvicenzi]

So Pvicenzi, would you buy a locking folder from a maker who told you "The lock works great IF you don't accidentally hit the spine of the blade on anything"?

I own and use many folders with no lock at all.

 

[stabman]

I think that flipping the cylinder closed is not so much that you will damage the mechanics of the gun, Its just that doing so is what causes worn blueing around the cylinder stops . Something I always note if buying a used revolver.

No, it can damage the actual gun.
Disassemble an average revolver, and check out the diameter of the pin involved.

 

[Mikel_24]

Um, I've got some bad news for you on that one, Mikel_24. In my experience with Leatherman Charges, the 'lock' on the knife blades is next to useless. I'm not talking anywhere near a 'spine-whack' here, I'm saying those liner-locks will not be forgiving of even a slight bump on a sofa! Be very careful!

Regards,
3G

Crap... I happen to carry mine right now. I just checked it and... well... give it a few taps agains my wooden desk here in the office and it help up well. The liner lock seems to be pretty well centered. Anyway, thanks for the heads up. I will keep being as carefull from now on as I have been before.
Mikel

 

[tirod3]

I stand by my earlier statement that if a lock fails, it is more likely the fault of the user than the manufacturer. If you want to whack a knife into a desk, get a large fixed blade. I cut things every day and in 41 years of using knives, I still have all my fingers, and I've never had a lock fail. Use folders only for cutting. If you need to stab or chop, get out the fixed blade.

The only - only - part of this I disagree with is that manufacturers are certainly capable of making locks prone to failure.

Liner locks are the worst culprit, and the worst combination seems to be a thin liner on a short leaf that attempts to mate to a thin blade in soft bearings. The beveled ramps on the engagement surface act to allow the liner to slip to the unlocked condition, and the materials are chosen for economy, not the necessary natural galling that some combinations exhibit.

So, a cheap liner lock with a thin leaf and teflon bushings tends to unlock more often than a thick liner lock with bronze bushings. Frame locks are generally even tougher to fail because the liner equal blade thinkness, and materials such at titanium are very "sticky" when engaging cutlery steel.

Now, if the cheap liner lock also has FRN grips, the maker then includes liners to stiffen it because the flexibility of FRN can actually contribute to walking the liner out of engagement. Add in the range of production tolerances, checking a few of every 100 at best, and requiring a daily quota, you get knives at a price point which guarantee some failures when spinewhacked. I own two - a Buck Tarani, and a Kershaw Boa.

Yes, spinewhacking is a dynamic test - just like slamming a revolver cylinder shut, which no maker I know of suggests is good practice. In some circles, it's considered a sign of incompetency to do so. For knives, however, a test can expose the inherent weakness of a knife before you give it full trust, and a method to check during it's life.

As said, the problem is how to measure the forces, 5 pounds or 50. I would suggest that if you can do it by hand, you're covering what you could do - which is a lot more realistic than vising it up and beating on the blade with a hammer.

Understanding the physics is key - apparently Spyderco does. Mr. Glesser makes knives and uses the practice. Given his credentials and parameters, there are still some who question it, a given on the all-empowering internet.

 

[allenC]

I own and use many folders with no lock at all.

But you didn't answer the question.

Would you buy a locking folder from a maker if that maker told you "The lock is fine but only IF you don't accidentally hit the spine on something"?

 

[pvicenzi]

But you didn't answer the question.

Would you buy a locking folder from a maker if that maker told you "The lock is fine but only IF you don't accidentally hit the spine on something"?

What manufacturer says that?

 

[marcinek]

Valid test. You never know when you might have to stun an enemy desk.

 

[allenC]

What manufacturer says that?

It's a hypothetical question for debate.

So, again, Would you buy a locking folder from a maker if that maker told you "The lock is fine but only IF you don't accidentally hit the spine on something"?

I'm guessing that you would not be willing to pay your hard earned money for a locking folder that fails to remain lock whenever moderate force is applied to the spine.
And since there are plenty of knives out there which pass the spine-whack-test, I can't see why anyone would choose a locking folder that fails.

And I really don't understand those who choose to never even see if their knife would pass such a harmless test.
It does not damage the knife in any way....we're only talking about a little wrist snap onto a carpeted floor or the bottom of your shoe.

 

[Blindeyes]

I say it is not a valid test. You don't use a knife in that manner, ie cutting with the back of the blade or using the back of the blade as a hammer.
How are you going to use a knife that way that you do not want the lock to fail. The lock shouldn't fail in the manner the knife was meant to be used, for example if you where widdling wood the blade should stay in the locked position.
You don't test a hacksaw blades strength by smacking the blade on the sidewalk do you.

 

[allenC]

I say it is not a valid test. You don't use a knife in that manner, ie cutting with the back of the blade or using the back of the blade as a hammer.
How are you going to use a knife that way that you do not want the lock to fail. The lock shouldn't fail in the manner the knife was meant to be used, for example if you where widdling wood the blade should stay in the locked position.
You don't test a hacksaw blades strength by smacking the blade on the sidewalk do you.

Then why even have a locking folder?
If we always use our knives the way they were meant to be used then we would not even need a lock on our folders.

But the sad truth of the matter is this:
Humans are not perfect.
Humans make mistakes.
Humans have accidents.

Locking folders (at least the ones that stay locked even if the spine of the blade is accidentally hit) are much more forgiving of human error.

But a locking folder that folds when the spine is hit is no more forgiving than a slip-joint folder.
In fact, at least most slip-joints have a backspring to resist closing....but a knife like a liner-lock or frame-lock that folds whenever the spine is hit is probably the worse possible knife to carry and use.

I really don't understand why anyone would defend a knife that can't pass such a harmless and simple test.
I've did the SWT on at least 100 knives over the years, and only three failed.
And none were harmed by the test.

I'm very surprised that there are folks here who outright would never do the SWT.

Do they think that they will not be able to control their own hand and wrist strength and somehow destroy the knife by giving the spine a firm whack on the carpeted floor???
Heck, a knife that is destroyed so easily is definitely not a knife for me!

Or are they just afraid that their knife might not measure up?

 

[Keith Montgomery]

I don't think there is anything wrong with the spine whack test as long as it isn't overdone.

 

[3Guardsmen]

I say it is not a valid test. You don't use a knife in that manner, ie cutting with the back of the blade or using the back of the blade as a hammer.

Right, because those are the only possible scenarios where the back of the blade could come in contact with (read: smack) something. Tell that to a co-worker of mine who almost lost a finger when his folding knife's blade folded on him (read: lock failed) as he was withdrawing the blade from a piece of cardboard he was cutting and inadvertantly smacked the spine on a cabinet.

How are you going to use a knife that way that you do not want the lock to fail.

Are you serious? We all want our locks to fail! Didn't you know that? We all flock to BladeForums to find the best possible EDC folder with a faulty lock, just so, God Forbid, if we make a mistake while using said 'grail EDC folder' we can come brag about how we're only able to pound out these posts with the 3 fingers we have left!

The lock shouldn't fail in the manner the knife was meant to be used, for example if you where widdling wood the blade should stay in the locked position.

First off, it's whittling, not "widdling," and a locking folder isn't required for it. Heck, locking folders aren't usually even preferred by folks here for the purpose of whittling. Can't you think of anything else that requires a locking folder that stays locked?

You don't test a hacksaw blades strength by smacking the blade on the sidewalk do you.

Not a very smart comparison on your part. I suppose you choose to use a hacksaw for hunting and your daily cutting needs, right? I guess you're used to using a hacksaw in confined/cramped areas as well? I imagine you then think that hacksaws are marketed towards Law Enforcement, the Military, and Emergency Rescue personnel as fail-proof tools, suitable also for back-up use as self defence implements? Get real!

Regards,
3G