Spine whack testing: valid or not?

Is it a fair practice?

  • Yes, it's a valid test.

    Votes: 23 18.0%

  • No, it's a pointless and stupid test.

    Votes: 58 45.3%

  • It's more complicated than a simple "yes" or "no" answer.

    Votes: 47 36.7%
  • Total voters
    128
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Guy McVer

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Like it or not, lock failure on a folder is a real issue that does happen. Something that a lot of people like to do is whack the spine of a folder on a block of wood to see if the lock will fail. A surprising amount of them do in fact fail that test. The price of the knife seems to have little to do with it. It could be a cheap knife and pass the test with flying colors, or it could be an expensive knife that fails with a minor tap.

But there are mixed opinions on whether it's a valid test at all. I have seen a lot of people claiming that it's a pointless test and makes no sense to do. I'm not sure how true that is. I do think that a simple spine whack doesn't replicate all of the conditions that a knife will be under when in use. Grip pressure, lateral and twisting force on the blade, debris getting inside the internals or perhaps oil working its way into the lock mechanism? I think these conditions could potentially affect the lock in ways that aren't replicated by whacking the spine on a block of wood to cause a sudden sharp impact.

Regardless of how you might feel about testing a blade lock this way, if I spent a few hundred dollars on a locking folder, then I would not be happy to see the lock fail this test so easily.

What is your view on testing a folder this way? Does it make any sense to you or not?
 
I could throw a loaded gun on the ground and it could fire off a round. Not a bad a gun, just a negligent misuse of it. Thats the 'spine test' to me.

Use a tool correctly and it lowers the chance of failure or injury. 'Correctly' comes from education and experience. Not abuse, misuse or negligence.
 
Delgadonine said:
I could throw a loaded gun on the ground and it could fire off a round. Not a bad a gun, just a negligent misuse of it. Thats the 'spine test' to me.

Use a tool correctly and it lowers the chance of failure or injury. 'Correctly' comes from education and experience. Not abuse, misuse or negligence.
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Big nope (for me) to either : any gun that goes off when dropped, or knife that fails a spine whacking ! :(:thumbsdown::thumbsdown:

Especially a gun or knife for fighting, or other uncontrollable circumstances .
 
Thought it was pointless til I was helping my uncle gut his house to renovate, cut something in a corner, and pulled the knife out smacking the spine on a beam.

I was pretty happy it passed that spine wack "test".
 
The worst cuts I've gotten were from me testing to see if a lock was safe. After I stopped worrying about it, I stopped getting cut.

The test makes sense but a lot more goes into it. Like everyone else, I want to know my folder is safe. It's nowhere near a perfect test but it's 1 way to show what it takes to fail the folder. What you do with that info is up to you.
 
I was talking with a mechanical engineer once, several years ago. The subject of the validity of non-laboratory testing and variables in the tests came up. He was even familiar with batonning and spine whack testing of knives. While he certainly had a lot of different things to say about it all, the most important thing was this: this whole story is going nowhere and I made it all up. None of this actually happened.

Sam⚔️⚔️
 
Getting a good feel for your knives is important, beating the ducks off the spine to see what happens is not.

So to me, it's nuanced, in that yes I do often tap my spines to get to know them and diagnose any lock slip tendencies or other quirks of the lockup. But I'm not going wild on them, not much more force is used than what I do when I test for blade play, because there is no reason to put the lockbar through unnatural and unnecessary wear. Every knife is a little different in terms of what it's built for and so my limited testing is always done with the knife in question in mind as well.
 
DocJD said:
Big nope (for me) to either : any gun that goes off when dropped, or knife that fails a spine whacking ! :(:thumbsdown::thumbsdown:

Especially a gun or knife for fighting, or other uncontrollable circumstances .
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Even the greatest can drop, fumble or even throw an interception. Don't blame the ball. User error.
 
My experience with spine whack testing is limited. But I did it a few times when I was younger. Endura passed. Tri-ad lock passed. Ganzo failed. But the Ganzo would even close if I held it in Filipino grip and put pressure on the spine with my thumb, so.... In any case, I voted "more complicated than a simple yes or no answer"
 
NG VI said:
Getting a good feel for your knives is important, beating the ducks off the spine to see what happens is not.
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Agreed
NG VI said:
So to me, it's nuanced, in that yes I do often tap my spines to get to know them and diagnose any lock slip tendencies or other quirks of the lockup. But I'm not going wild on them, not much more force is used than what I do when I test for blade play, because there is no reason to put the lockbar through unnatural and unnecessary wear. Every knife is a little different in terms of what it's built for and so my limited testing is always done with the knife in question in mind as well.
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I actually did this recently with 2 of my Hinderers, against the palm of my hand (not crazy hard, but still not smart I know), and they were fine.
I really do question the validity of that recent youtube video that shows them failing.
The same guy who posted that has also previously mentioned he modifies the lockbar tension on his knives to his liking.
🤔
So no, I don’t consider it anything but
antagonistic clickbait if it’s not done scientifically. Cold Steel’s older videos were interesting.
 
Define "whack" . Everyone I've whacked with whacks different, are we whakin by hand or with a tool? How hard a whack is too hard?, or how many times should it be whacked? What are we whakin against? Why wack on folders anyway?
Ive got better things to whack on. Whack too much on anything and it will eventually fail.
 
elasmonut said:
Define "whack" . Everyone I've whacked with whacks different, are we whakin by hand or with a tool? How hard a whack is too hard?, or how many times should it be whacked? What are we whakin against? Why wack on folders anyway?
Ive got better things to whack on. Whack too much on anything and it will eventually fail.
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Meanwhile, 'Spinal Tap' needs a new drummer...
 
The only way this is a valid test if you’re treating the feasibility of using your folding knife as a hammer. If that’s the case it also works for treating fixed blades as hammers.


If that’s the intent, whack away.
 
ShaiHulud said:
Read this article from a guy who spine whacked knives then disassembled them to inspect the locking mechanism and found that it damaged them
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What article? I don't see an article.

You guys got me curious about this spine whacking stuff; so I took my GEC 48 out of my pocket, opened it, and gave the spine a two finger slap. I'm actually glad I tried it because the blade slammed shut so fast I would have thought it didn't even have a lock. Oh, wait...:oops:
 
I think the spine whack works pretty well to test how the lock surfaces mate and how much engagement you have. If the mating surface angles are optimized too much for reduced wear, they can slip when exposed to a sudden shock. You could do this if you quickly stab something and hit the angle wrong or glance off something hard or hit the back of the blade by accident. I don't think there's a safer way to simulate those situations.

That being said, it's not the only thing that matters, and some of my knives aren't going to be seeing any use like that.
 
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