Spine Whack Test

[Ankerson]

I don't think it's a good idea for the end user to do spine whack tests, maybe a few light taps. The spine whack will take years away from your locks life, in fact maybe kill it alltogether. There is a certain amount of "room" for say a liner lock to move after wear or excess pressure to the lock faces, and you will likely use it up in impact tests. Even excess flipping open can wear out your locks like. (however, I like to build them to so you can flip till you get tired of it). In short, I say leave the testing to the guys how review knives and the makers.

Well said Andrew. :thumbup:

I also don't recommend spine whacking ever... Over Strikes are even worse.

A few light taps is fine to make sure the lock is working.

 

[KeithAM]

Serious response:

As an illustration, I remember a few years ago a unregistered user, Vinny, who was banned and rebanned numerous times for a variety of misbehavior, posted a video of a Benchmade 710 that failed a spine whack test. As I recall, he was hitting on the edge of a wooden bench or table, and the table had deep grooves in it from where he'd been whacking it.

I consider the Axis lock on the 710 to be very reliable. While there's a chance this guy got a rare lemon, I think it's more likely that he spine whacked the knife into failure.

Okay, here's the video. Note the marks on the bench toward the end of the video.

http://video.google.com/videoplay?docid=7553470131749739284#

 

[freq18hz]

No.

repeat:

No.

 

[CWL]

"I bought a new car to drive, but I'm concerned with the reliability of it, so I'm going to keep driving it into a wall until the front end collapses... then I'll know how tough it is!"

Would that make any sense?

 

[TheKnifeDude]

Oops I realized in my post #45 I messed up the link to the video, it works now http://www.youtube.com/watch?v=pDDQGmW2Hrg

 

[CWL]

Oops I realized in my post #45 I messed up the link to the video, it works now http://www.youtube.com/watch?v=pDDQGmW2Hrg

Once again, what is the point of that?

 

[Siggyhk]

I think the point is to show you that you can use other parts of the knife, besides the edge, without fear of the lock not working and folding on your fingers.
I think some don't like the idea that some folding knives can do more than just cut now-a-days. You'd think there would be alot more blunt-tipped, slip-joints being sold.

 

[Hawkings]

Once again, what is the point of that?

I think its to show that the knife is durable.

 

[CWL]

I think the point is to show you that you can use other parts of the knife, besides the edge, without fear of the lock not working and folding on your fingers.
I think some don't like the idea that some folding knives can do more than just cut now-a-days. You'd think there would be alot more blunt-tipped, slip-joints being sold.

"now-a-days?" Victorinox/Wenger manufactures over 25,700,000 SAKs each year... that's over 100K per day being manufactured.

 

[goodeyesniper]

serves absolutely no purpose. I may open up a new knife, grip it near the tip and try and push it closed, as well as check for play, but that's about it, and I doubt that constitutes as abuse. I would consider that a basic function check.

I don't know of ANY responsible knife behavior that would ever have the spine being rapidly, and forcefully hit putting sufficient closing pressure on it, except for maybe self defense. And, frankly, at that point you'd have more to worry about.

 

[Siggyhk]

CWL, I'm pretty sure you missed my point. That's not a problem though, especially for me. -Probably a good edit, by the way.

Anyhow my advice to anyone concearned is to:
1) Do whatever you want with your knives.
2) Try not to sound like a know-it-all, or a cry-baby when you don't agree with what someone else does with thiers knives.
3) Consider observing what others have done with thier knives, so you can perhaps learn a leason without doing it to your knives.
4) Don't trust a knife to stay open in an emergency if you were never really worried how well it would say open durring your normal daily activities.

 

[CWL]

CWL, I'm pretty sure you missed my point. That's not a problem though, especially for me. -Probably a good edit, by the way.

Anyhow my advice to anyone concearned is to:
1) Do whatever you want with your knives.
2) Try not to sound like a know-it-all, or a cry-baby when you don't agree with what someone else does with thiers knives.
3) Consider observing what others have done with thier knives, so you can perhaps learn a leason without doing it to your knives.
4) Don't trust a knife to stay open in an emergency if you were never really worried how well it would say open durring your normal daily activities.

Well, if you had posted this originally, I'd be agreeing with most of it. But you chose to write "You'd think there would be alot more blunt-tipped, slip-joints being sold."

btw, my edit was to add the SAK manufacturing quantities.

 

[hoopster]

I tried my Sage1 on the lip of a plastic barrel just out of curiosity since I've never "spine whacked" a knife before. I could get it to fail on the second or third whack just about every time.
It didn't do any visible damage and the knife still functions exactly as it did before the test. I don't put much stock in the test though as I fully trust the Sage1 linerlock to do what a lock blade knife should do.
I think it had more to do with the bounce or vibration of the impact rather than reverse blade pressure so it may not have failed on wood or something else. I don't have any desire to try though.

 

[termiteslayer]

Well, y'know...
I was having a chain problem with my snowplow today so I decided to try every single knife I have to solve it.
Apparently, all of my knives suck ass... seriously.


Guess I'm just saying I'd never attack a Siberian Tiger with a tactical pen.

 

[TheKnifeDude]

The reason why I care about lock strength / reliability so much is because I want my gear to be as close to infallible as I can get. Also I don't like to carry fixed blades. That's why I like strong folders, revolvers, and ak's. Some people may have to use their tools in ways they are not intended at some point. -Zeke

 

[termiteslayer]

The reason why I care about lock strength / reliability so much is because I want my gear to be as close to infallible as I can get. Also I don't like to carry fixed blades. That's why I like strong folders, revolvers, and ak's. Some people may have to use their tools in ways they are not intended at some point. -Zeke

I can't disagree with you in any way (except I'm not necessarily a fan too many rapid-fire boomstick owners with no management of some sort... lotta psyco's out there... different discussion, I guess), but a folder will always be a folder... disadvantaged by default.
Clint Eastwood once said, "A man has got to know his limitations".
Guess that why he went with a .44 mag.

 

[shecky]

I inadvertently discovered that my kershaw skyline fails the spine wack test. I was watching tv and tapping the spine on my thigh. Eventually I tapped slightly harder and the lock failed. I tried it a few more times and the same thing happened. I have to hit it on my thigh hard enough that if it was any harder, it would hurt.

I also tried applying pressure on the back of the blade. The lock did not fail during this test.

True enough. My ZT 0301 also folds with a small tap on a semi-hard surface, but won't budge an inch if a try to muscle it closed.

Folks are gonna hate me for this. These two instances would seem to indicate a good justification for the spine whack test. The difference between a sudden impact and a push may mean a great deal. But here are two knives that seem to have failed a relatively mild spine impact test.

One could certainly write off these failures as insignificant. I think this would be a mistake. The reason for a lock on a knife is to provide a modicum of insurance against accidents. While it's true that a knife user would not normally whack the spine an use, there is no telling what can happen during such accidental occurrences. A locking blade that disengages with an amount of force that would not cause harm to the tester (hitting on one's leg below the threshold of pain), or otherwise mild impact ("small tap on a semi-hard surface"), is effectively a slipjoint. Deceptively equipped with a locking mechanism.

 

[tradja]

I bet OP thinks we're a bunch of a**hats.

Is he technically wrong?

Back OT: OP, you'd have to own one to really understand.

 

[goodeyesniper]

Folks are gonna hate me for this. These two instances would seem to indicate a good justification for the spine whack test. The difference between a sudden impact and a push may mean a great deal. But here are two knives that seem to have failed a relatively mild spine impact test.

One could certainly write off these failures as insignificant. I think this would be a mistake. The reason for a lock on a knife is to provide a modicum of insurance against accidents. While it's true that a knife user would not normally whack the spine an use, there is no telling what can happen during such accidental occurrences. A locking blade that disengages with an amount of force that would not cause harm to the tester (hitting on one's leg below the threshold of pain), or otherwise mild impact ("small tap on a semi-hard surface"), is effectively a slipjoint. Deceptively equipped with a locking mechanism.

I wouldn't call that "deceptive" at all. The fact that some people might THINK they can stand up to certain rigors they were never designed to see is not the manufacturer's problem. The fact of the matter is that spine whacks are a huge weakness for liner locks and frame locks, you can have a very sturdy/reliable knife fail quite easily with a spine whack.

That said I can't think of many scenarios where spine whack would come into play unless you are carelessly slashing at something back and forth. Kinda like a safety on a pistol, IMO. If you're at the point where you're worried that if you pull the trigger, the gun will actually fire, then you're already a few steps past "bad decision making".

 

[Poez]

So many people on this forum repeat the mantra about a knife being a tool, not a weapon...
Complaining about misunderstanding from their co-workers and the general public...
So here you are - a spine whack shit... What has it to do with a tool?
You can do with your knives whatever you like - that is your business. But do not assume it is of such an interest to anybody. After all, anybody can do it!
I personanly do not care at all. I believe I am capable of using my knives in responsible safe manner.