Spine Whack Test

M

mrd74

Joined
Dec 1, 2001
Messages
607
What am I missing here? I fail to see the point of this test, unless the blade is double edged and the user is making back slashing cuts how does it apply to the daily use of a single edged lockblade folder.I've never had any kind of lock failure with any kind of knife lock in my life and was wondering why one would apply such a test to a knife that would never have that kind of force exerted upon it when used in a normal manner.I'm not questioning this test on the beefy stuff like folding Striders and other "extreme" knives but when spine whacking is applied to knives like the Camillus EDC as a standard durability test I just fail to see the point.Am I wrong and if so please enlighten me. :confused:
 
Try to think of slipjoints (ie blades in SAK/Multitools) and make sure all your fingers are clear of the groove. Now lightly jab the point into some solid object, and move the handle in a way so that the knife could close on you.
That's the reason why locks were invented.
Now if you have a folder, and let's say you're using it to chop into some stuff and got it stuck, when you manage to pull it free, the spine hit some hard object and the lock fails, then your fingers would just be like the problem above if your fingers are close to the groove, the blade will drive into your fingers.
Yes I'd say that the spine whack test is normally not need with everyday tasks that we do, but on some occasions we might need the lock to keep the blade from folding on our fingers, and you'd be glad to make sure your lock won't fail.
BTW which part of BC are you from?
 
I can understand your explanation in regards to the getting stuck while chopping theory.Since I only chop with fixed blades,machetes,hatchets,etc.I guess the test holds water it just doesn't apply to me as I'd never chop with a folder unless it was in the league of the Strider AR. In answer to "your" question,I live in Victoria,Capitol city of the Republic of Vancouver Island.
Mike
 
Well I must admit that you're right about how most uses you wouldn't encounter cases where the knife would be whacked on the spine, but if you got the lock for it, why not make sure it works well?
I'm in Burnaby myself.
 
A safety device that does not function properly is worse than none at all. Why do you need a locking folder at all? The spine whack test is designed to determine whether the lock is functioning properly. If you don't need a properly functioning lock, then you don't need one at all, and your needs would be adequately served by a non-locking folder. This may be the case in your situation. I prefer that my folders lock, and that they remain locked when closing pressure is applied to the spine. I spine whack my folders in order to ensure that they do, in fact, lock, rather than just taking the manufacturer's word for it.
 
The spine whack test, when done appropriately is a good way to test if the lock is fuctioning properly. This test should not be done with enough force to possibly damage the lock as some manufacturers consider this to be abuse and you will have to pay to get your knife fixed. Hitting the spine of the blade against your hand with moderate force should be enough to tell you if the lock is working properly.
 
The spine whacking test puzzles me. I like knives that I can be sure won't close on my hand and cut the s**t out of my knuckles, but really, how many quality knives need this test? I mean, before I even knew that good knives existed, (long ago) I bought cheap knives with cheap lock-backs that I was sure would not close on my fingers. I have never been in a combat situation (and I am pretty sure 90% or more of the people reading this post won't be either), So, unless you plan on putting you fingers between the blade and body of the knife, and slamming the back of the the blade against a cinder block or a tree, why worry about it?

-Dave
 
I re-read this whole post, and agree with KWM. I have a Strider GB folder, and it pretty much puts "spine whack" tests to shame. Just for the hell of it, because I am reading this post, and claiming that spine-whack tests are stupid, I, myself (being a stupid fella...) decided to spine whack a few other knives... Well, all of my fixed blades passed with flying colors... now onto my folders... All of my Spydies did great... my Emersons did great.. Strider GB.. once again... great...Al Mar... great.. cheap copy of MT LCC D/A... Great....

Point is.. Spine Whack Test = S**T... Even with a slip joint knife I manage to keep fom getting my fingers cut... so can anybody else...


Later....
 
read an issue of tactical knives, the knife tests,they whack 'em all

not all will pass, some of the higher $$ brand(s), w/a 'space age' super lock, fail the test, and the maker says it constitutes abuse

and let me clarify, ya dont really whack it into a 4X4 (although the guys at tac knives do) a simple slap into the palm is enuff for me

my knives need to lock, agree w/medusa, if ya dont need a lock, buy a slipjoint and 'make do'

me, i'll buy a good liner/axis/lock back, and never look back

good luck, watch those fingers

sifu
 
First post...thought I would jump in. I've actually found it just as effective to hold the back of the blade and wiggle the blade side to side while trying to close it with moderate force. I was surprised to find that a few lower end knives would jump out of their locked position when flexed that way. My usual heavy duty carry knife right now is a Spyderco Chinook. Opens and locks like a bank vault. I'm pretty sure I could drive the blade into a tree and rappel off of it if I had too. Thats a pretty overbuilt knife. the only folder I've got that might even come close is an old original Al Mar SERE. Another really tough knife.
 
FYI, my Mini AFCK (liner lock) failed the spine whack test. My full-size AFCK (liner lock) passed...
 
You will be very surprised at what knives pass this test and which ones don't. It opened my eyes a bunch!
Greg
 
Iverson :

I have a Strider GB folder, and it pretty much puts "spine whack" tests to shame.
Click to expand...

Not from the source :

Mick :

If you whack your knife against something solid, a log, the ground, etc. It will more than likely fail.
Click to expand...

ref :

http://www.bladeforums.com/forums/showthread.php?s=&threadid=194970

That being said, my Buck/Strider was stable under spine impacts, and yes off of fixed objects, a slip joint is stable if whacked off of an object that can move freely enough. However the same folder could easily be released by light torquing / prying.

As for spine whacking, there are lots of ways a lock can recieve a load that can induce a release just as if it got a spine impact (stabbing, forceful dynamic cutting etc.) . The test indicates a type of security which you may or may not want. It is up to the user to decide if it is necessary for them which depends obviously on what they indend to do.

There are many past threads which discuss this in great detail.

-Cliff
 
I responded to a thread like this one a few weeks ago, and again my views have not changed. To wack ,smack whatever your knife against a hard surface just to check its lock up to me is abuse of the knife. If its not abusive then why do many manufactures consider it abuse.I can agree with KWM about using palm pressure.I you want to stab get a fixed blade.knives arnt hammers/prybars they designed to cut. Im probably going to get flamed for my opinion but thats the way i see it.
 
david allen :

If its not abusive then why do many manufactures consider it abuse.
Click to expand...

What about the manufacturers that don't. Abuse is not some kind of universal standard across all knives, what is abusive to some isn't to others.

-Cliff
 
This whole issue seems to be a never ending debate. I think the spine whack test does serve a purpose. It tells you if the lock is funtioning properly at the time you did the test. When done judiciously it will tell you if the lock will work when it is used at a later time. If you hit the spine of your knife hard against a 2by4 all this told you is that it worked this one time. If while doing the test you somehow damaged the lock (and believe this could and has happened) you have just given yourself the overconfidence that it will work the next time it needs to. The only thing that a severe spine whack tells you is that the lock worked long enough to pass the test.

As far as companies considering or not considering a spine whack test as abuse goes, I believe that pretty well all companies will consider it abuse after a certain point. I have heard of a person that takes his knives and attaches them to a 3 foot stick, then swinging the stick like a baseball bat he hits a tree or a work bench with the spine of the blade. If it does not pass he thinks the knife failed in it's duty. Any knife manufacturer that would not consider this abuse is tremendously confident in the toughness of their lock.

It does not matter how much force you use to perform a spine whack test. If you damage the knife be prepared to pay for repairs. If the company feels that the knife should have passed your test and does not charge you then great, but if they do feel it was abuse don't whine about having to pay to get it repaired. It is your choice to do this test and it is your knife to do with as you please, just don't expect the maker of the knife to think the same way you do as to whether the test you performed was appropriate or not. As long as you are willing to accept this, then whack away to your hearts content.
 
For my own knives, I will test by hand pressure (with my fingers of the other hand safely aside) on the back of the blade to see of the lock moves (particularly with a liner lock). Also will pull the blade back as in cutting pressure, as that will sometimes move a liner lock over.

IMO, the spine whack test, esp. if done often, is gradually destroying the lock. Some people have stated that the scary thing about certain locks is that they will pass the spine whack test for months or years, then suddenly start failing. It's really no mystery. Each time the spine is whacked hard, it's causing a small amount of damage/wear against the lock. It prematurely wears out the mating surfaces of, say, a liner lock that might have started out as very reliable. A proper locking folder is a precision mechanism not designed to be banged up as a regular matter of course. If I need a knife I'm going to be banging around I will choose a fixed blade and eliminate the possibility of a folding blade closing on my hand. I know it's an old argument, but a knife with a pivot will never stand up to the abuse of a fixed blade, no matter what the lock strength or hype.

That said, I also have used slipjoints most of my life, and have been cut many times, but so far never due to one closing on my hand due to their lack of a lock.
Just my .02, FWIW.
Jim
 
KWM :

It does not matter how much force you use to perform a spine whack test. If you damage the knife be prepared to pay for repairs.
Click to expand...

Like any "test" or just use in general, damage should only be payed for if it should be expected and thus it comes down to how the knife is being promoted. If I take a Trailmaster and chop down a tree and blow a piece out of the edge I don't expect to have to pay to get it fixed. However if I take it and cut the windshield of a car then it would be reasonable to pay to get the edge reset. Same thing with locks. Anyone claiming to have the strongest and most durable locks around, with 1000+ in.lbs break points should not be complaining about banging the knife off of a table, which you can do a thousand times to a decent lock back without problems. The simplest arguement for them is this : there are makers that don't have a problem with them, thus anyone who does is promoting a directly inferior knife (in that one aspect of course).

-Cliff
 
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