liner lock problem

[STR]

Pressure testing from putting physical force on the spine of the blade and the point tip third in particular is a good test. I'll tap lightly on my boot toe if it defeats from either of these well, 'hard use' it ain't! Send it in with a note detailing that it defeats from simple spine pressure on the blade. Simple spine pressure is real world. It happens in something as simple as cutting down a cardboard box or field dressing game or other such real world uses. Not that an Emerson is the best for hunting purposes, particularly tanto models but some of the V grind models can do it and I know some that use one for that on occasion. Now of course Emerson has one for hunters although I forget the model.

Spine whacking the thinner titanium and stainless liners and even the thicker ones can indent the lock contact and increase the wear prematurely. Just like anything new you should give it time to break in but even new it should not be sliding off the contact to secure the blade from simple spine pressure. If one of mine did I'd want to know about that to correct it ASAP.

I think it could be argued that strikes to the spine could indeed happen in a close quarters combat knife. I also believe that if the lock defeats from simple spine pressure tests or light taps to the toe of your boot that it will certainly defeat readily in a hard stab defensive strike. In short it cannot be trusted if it defeats that easily. Personally a folding knife for self defense is a last resort and if needed a liner lock would certainly be my second to last choice for anything that would involve straight stabs or thrusts with slip joints being the last choice in a folder I'd even try to use for defense but what do I know.

STR

 

[MORIMOTOM]

true enough, but simple spine pressure and hitting it on a hard surface are not the same thing.

op said he used a hard surface, you use your boot.

we don't know how much pressure he applied to the spine prior to failure.

 

[Splat]

Spine whacking is abuse. In normal, non-combat, use of a knife I don't think you could ever duplicate the force of a strong spine whack. I can't figure the cutting method you would be using to need to go back on the spine that hard. If you want to baton using a folder then you're asking for trouble. I test my knives' locks by pushing on the spine with moderate force. My then-2-months-old Snubby actually failed this test and was fixed by Emerson. None of my other knives have ever failed this test and are still reliably being used.

 

[Haze]

Really?!? It surprises you that a 'fighting folder' ("CQC" doesn't stand for "Custom Quilt Cutter"), designed for 'professionals in harm's way,' might somehow end up getting the spine of its blade smacked?

Regards,
3G

I didnt say I was surprised about anything at all. However I would be surprised
if a knife was actually used to defend ones self as that is a rare event indeed.

Knife attacks tend to be rather one sided and dont last for very long.
You are either the one getting attacked or are the attacker. People tend to
use the sharp side of a knife for this part, even a junkie can get that right.
If your trying to say a knife attack will last long enough to become a duel
where you will be using blocks and traps with the spine of the knife then you are very much mistaken.

So, back in the real world I still dont see what attacking the spine of your
knife is replicating in any way. Even when stabbing the pressure is not
applied in the same way as an actual "hit" to the spine of the blade.

 

[3Guardsmen]

Spine whacking is abuse. In normal, non-combat, use of a knife I don't think you could ever duplicate the force of a strong spine whack.

What kind of knives does Emerson make?

 

[3Guardsmen]

I didnt say I was surprised about anything at all. However I would be surprised
if a knife was actually used to defend ones self as that is a rare event indeed.

What are Emerson knives designed for again?

Knife attacks tend to be rather one sided and dont last for very long.
You are either the one getting attacked or are the attacker. People tend to
use the sharp side of a knife for this part, even a junkie can get that right.
If your trying to say a knife attack will last long enough to become a duel
where you will be using blocks and traps with the spine of the knife then you are very much mistaken.

So, back in the real world I still dont see what attacking the spine of your
knife is replicating in any way. Even when stabbing the pressure is not
applied in the same way as an actual "hit" to the spine of the blade.

Underlined portion was answered another thread:

I think someone needs to clearly define the terms "spine-whack" and "spine-tap," then we can really debate the issue. For my own purposes, I consider a spine-whack to be a full strength, full arm's swing of a folding knife's blade's spine into a hard (ideally wood) object. I consider a spine-tap to be a half strength, half arm's swing (no shoulder motion) of a folding knife's blade's spine into a bit softer of an object (ideally the tip of a boot).

If you accept my definitions of those terms, I'll tell you flat out that I've had several well known, well made knives that have failed the spine-tap, including two Spyderco Manixes, the main blade of every Leatherman Wave and Charge model that has passed through my hands, and I've had a few of 'em, a Spyderco Stretch (the original version), two Boker Subcoms, a SOG Twitch, a CRKT Pointguard, and a CRKT M-16 "big dog" tanto. I think that anybody who keeps a knife with even the idea of ever possibly having to use it in a rescue, survival, or God Forbid, a last ditch SD situation is a complete and utter moron if they don't at the very least give that knife an occasional spine-tap!

Most people don't plan on accidents happening, like bumping the spine of the blade on a hard object (table, car door, tree, toolbox, you name it) while withdrawing the blade from an object being cut, but guess what, accidents like that happen every single day! Let me give you a scenario. A Firefighter wants to cut a vehicle collision victim free from his seatbelt, so out comes the rescue folder. The Firefighter shreds the seatbelt apart with his blade, but while pulling the knife back towards him, inadvertantly smacks the spine of the blade on the inside of the wrecked car's door, causing the lock, which should have held up, to fail. Best possible outcome, the Firefighter was wearing great quality gloves and his knife's blade is fairly dull, resulting in a cut glove and a minor injury to his index finger. Worst possible outcome, the Firefighter had crappy gloves, or didn't have them on, had a scary-sharp edge on his knife, is now minus a finger or two, and is on his way to the ER with the collision victim!

For those who say that spine-taps are abusive, I certainly hope you never find yourself in a situation where the integrity of your folding knife's lock is less than stellar and is inadvertantly tested! Luckily, I'll never be in that group.:thumbup:

Regards,
3G

 

[Lycosa]

I switched to a FB.

 

[3Guardsmen]

I switched to a FB.

Smart choice!:thumbup:

 

[MORIMOTOM]

the problem, at least imo, is not in testing the locks reliability.

but how much pressure is appropriate to apply to the lock in doing so. for example, spyderco (i think) uses a machine that applies direct pressure to the blade to test the lock failure point. it does not include "whacking" the spine.

like str, if someone were to tap the spine on a boot heel or book, this would be an effective method with little to no chance of peening the lock or blade tang. hitting it on a hard surface like a counter or desk could impart significant shock to the knife resulting in a damaged lock, that ultimately may fail as a result. would it have failed if w/o the resulting damage?

no folder is designed to have the spine used as an impact tool. at the same time, a lock shouldn't fail, within reason. every lock has a failure point, and with the proper amount of force this can be achieved.

the op has been very vague as to what constituted his spine whack.

did he use a hammer swing?

did he just tap it a few times? how hard and how many times?

somewhere in between?

i normally advise against this because there is to much margin for error in performing this "test".

 

[Lycosa]

Well said, Mark. :thumbup:

 

[Splat]

What kind of knives does Emerson make?

Emerson makes solid built knives. I use all my knives the same way and for any task I ask of them. None are designated for certain chores.

 

[Haze]

What are Emerson knives designed for again?

Thats called marketing, seems it works too .
EKIs are just folding knives not that much different than any other.

Underlined portion was answered another thread?

Knocking the knife blade by accident is not the same IMO.
I have hit my knife off things many times and never had it fail.

If you like the spine whack test then bully for you man but there
is also folks who dont like it or see the point.

 

[3Guardsmen]

Spine whacking is abuse. In normal, non-combat, use of a knife I don't think you could ever duplicate the force of a strong spine whack.

What kind of knives does Emerson make?

Emerson makes solid built knives. I use all my knives the same way and for any task I ask of them. None are designated for certain chores.

That's not an answer to the question I asked. Does Emerson make 'fighting folders,' designed for "CQC (Close Quarters Combat)," or doesn't he?

Regards,
3G

 

[3Guardsmen]

EKIs are just folding knives not that much different than any other.

I doubt Mr. Emerson would agree with you on that one!

Knocking the knife blade by accident is not the same IMO.
I have hit my knife off things many times and never had it fail.

Then you have a good, reliable lock. That's the whole point of performing a spine whack/spine tap, to test the reliabilty of the lock. Better to find out it's defective prior to the "accident" happening, wouldn't you agree?

If you like the spine whack test then bully for you man but there
is also folks who dont like it or see the point.

I like the spine tap test I outlined in my quoted post.

Regards,
3G

 

[3Guardsmen]

well, how hard did he whack the spine?

a tap to one may be considered a whack to someone else. and vice versa.

I agree. It is hard to quantify.

the problem, at least imo, is not in testing the locks reliability.

but how much pressure is appropriate to apply to the lock in doing so. for example, spyderco (i think) uses a machine that applies direct pressure to the blade to test the lock failure point. it does not include "whacking" the spine.

like str, if someone were to tap the spine on a boot heel or book, this would be an effective method with little to no chance of peening the lock or blade tang. hitting it on a hard surface like a counter or desk could impart significant shock to the knife resulting in a damaged lock, that ultimately may fail as a result. would it have failed if w/o the resulting damage?

no folder is designed to have the spine used as an impact tool. at the same time, a lock shouldn't fail, within reason. every lock has a failure point, and with the proper amount of force this can be achieved.

the op has been very vague as to what constituted his spine whack.

did he use a hammer swing?

did he just tap it a few times? how hard and how many times?

somewhere in between?

i normally advise against this because there is to much margin for error in performing this "test".

Very good points you raise! Joe Talmadge has put a lot of effort into 'standardizing' the "test," but we've still got a way to go.

Regards,
3G

 

[Haze]

Fair enough, I can see your point.

Emerson knives are clearly my favorite production knives but weather or not
any one agrees with my opinion they are "just" folding knives and have the
same limitations as any other folding knife does.

How you happy your self with those potential limitations is up to the individual :thumbup:

 

[3Guardsmen]

Fair enough, I can see your point.

Emerson knives are clearly my favorite production knives but weather or not
any one agrees with my opinion they are "just" folding knives and have the
same limitations as any other folding knife does.

How you happy your self with those potential limitations is up to the individual :thumbup:

I can most certainly agree with that, my friend!:thumbup:

Emersons are great knives! A BM 970/Emerson and a Spyderco Delica are what got me into knives, back in 96, and I guess I sort of (unfairly) hold my Emersons to a higher standard, since they're so well built. I have yet to have an Emerson fail any spine tap/whack tests I've given 'em!

Regards,
3G

 

[Zozo*HC*]

My opinion is that if they are enogh strong to stab someone is 100% perfect for me(EKI knives are designed for this purpose ). For hardcore chores only FB knives.

My locks never failed on me, i always do some spine whack on my knees and no problem for me. IMO in case of stabbing the main part of force affect the Pivot and stop pin, and the lock gets the smallest part of the "torture". I saw nutnfancys youtube video, he "stab tested" the ontari rat 1 folder, after 10-15 strong stabs the lock still hold on and he just had to tighten the pivot a bit. a 25 buck knife can survive a stab test i think an EKI 100% can outperform it if the lock is not defective.

just my 2 cents.

 

[pvicenzi]

Proponents of the whack can't even agree as to what exactly it is. Hard smack on the edge of a counter? Light tap on a soft boot sole? Moderate tap on a hard surface? To top it off, a lock that passes this test, is not necessarily reliable.

 

[Splat]

What kind of knives does Emerson make? That's not an answer to the question I asked. Does Emerson make 'fighting folders,' designed for "CQC (Close Quarters Combat)," or doesn't he?

I don't care what he markets them as. I use them how I want to.