BladeHQ "Lock Strength Test II": Dynamic Pressure and Suspicions Confirmed

[B.F.U]

I'm sure many of you remember BladeHQ's first lock strength test video. It caused a lot of discussion and some disagreement about the test and the results. Well they did another one, this time using a mechanical winch using dynamic pressure rather than the static pressure that they used with the weight hanging rig in the original video. Check it out:

BladeHQ posted new working link in post #46

https://youtu.be/AzssI3u5D-0

What do you think?

(If this has been posted please let me know, I didn't find any threads.)

 

[B.F.U]

For me, this confirms several things that I've thought for a long time. First although frame locks can hold more weight than liner locks, they're not necessarily safer because they are more prone to lock slipping. Now again I know that this is only one test, but the results seem pretty clear, and when thinking about the design of a frame lock, it seems evident to me that in any grip but a hammer grip, or when cutting toward the lock, the "safety feature" of your grip against the lock is nullified. I do wish they would have used a higher quality liner lock.

Second, I've always thought that ball bearing and bolt locks, or any lock design that puts the lock between the tang of the blade and a liner or the body of the handle will be stronger than other locks. I was surprised the sage held more than the Manix, but I wonder if that was simply because the Sage has deeper screws than the Manix (I don't know, I don't have one).

Finally, I am glad the back lock did well. I know for a fact that I can create enough dynamic pressure, even in an accidental slip of the hand, to fail the liner and frame locks. I doubt I could as easily break a blade in half at the pivot. I wish they would have tried a knife with the updated midlock as on the Native 5, even the lightweight, as I know first hand it is a greatly improved design.

 

[Arviee]

Thanks for the link, interesting stuff! Really curious about AXIS locks, do you guys have any idea where they would stand?

 

[B.F.U]

Thanks for the link, interesting stuff! Really curious about AXIS locks, do you guys have any idea where they would stand?

I'd think they'd be in the area of the ball bearing and bolt lock, due to similar mechanics. Maybe slightly less because of a more angled tang and weaker spring.

 

[Scurvy092]

The back lock only does well because the cable goes around the lock bar and effectively holds the lock closed. They had the same issue last time. The handle failed because all The hanging weight was over the lockbar.

 

[BladeScout]

Interesting test ....to a degree (no pun intended).

Surprised about just how strong several of the locks were and what they held up to.

But.....do these tests (and 'spine whacking ') have any validity in the real world for us ordinary folder users.

 

[Scurvy092]

But.....do these tests (and 'spine whacking ') have any validity in the real world for us ordinary folder users.

Nope.

 

[B.F.U]

Nope.

You don't think you can create 50 pounds of dynamic pressure if your hand slips during a tough cut? Because I know I can, and I've had locks deform or slip and unlock in normal use. If people don't think they ever slip up or make a mistake while cutting, I don't know why they don't use slipjoints exclusively and stop buying locks altogether.

These are extreme tests, without a doubt. But I don't think these tests are in the same category as, for example, Cold Steel's swinging spine whack and over strike tests. Those are abusive. I would consider these tests much more credible and applicable to real world use because they use even, progressive, dynamic pressure with an easily measurable outcome.

 

[B.F.U]

The back lock only does well because the cable goes around the lock bar and effectively holds the lock closed. They had the same issue last time. The handle failed because all The hanging weight was over the lockbar.

Well, people constantly claim the frame lock is so safe because the hand keeps the lock bar from moving....

I'm not saying that what you said didn't happen. I would like to know why the lock would lift up under pressure even if the loop weren't pushing on it though. The geometry of a back lock doesn't really lend itself to that happening, hence no real mention of back locks having lock slip (like liner and frame locks, because their geometry does lend itself to movement in that direction).

 

[BladeScout]

You don't think you can create 50 pounds of dynamic pressure if your hand slips during a tough cut? Because I know I can, and I've had locks deform or slip and unlock in normal use. If people don't think they ever slip up or make a mistake while cutting, I don't know why they don't use slipjoints exclusively and stop buying locks altogether.

These are extreme tests, without a doubt. But I don't think these tests are in the same category as, for example, Cold Steel's swinging spine whack and over strike tests. Those are abusive. I would consider these tests much more credible and applicable to real world use because they use even, progressive, dynamic pressure with an easily measurable outcome.

You redacted your post and understandably so - I didnt insult you nor the test, so there is no need for any of us to get our collective knickers in a bunch

I said, that I did find the test interesting and indeed entertaining and you are certainly entitled to finding any test perfectly valid.

But folders are folders - not fixed blades. With sensible folding knife use, I just dont see these forces being applied as an issue. If you use any knife as intended, You should be cutting away from you. Of course a lock can fail, as You say.

As for who should use slipjoints exclusively - my retort would be, that if one intends to bring that kind of pressure (which you talk about) on a folding knife, maybe one would be better off with a fixed blade exclusively

How ever, I dont intend to get into a mud slinging match over this. There is a slight possibility, that I simply dont take the tests nor spine whacking too serious nor as the holy gospel and/or and indicator of how hard I should use MY knives. You on the other hand are free to interpret them as You please, thats your perogative.

Caveat: I think we can both agree, that having the strongest lock possible is a good thing. See, there is some common ground

 

[pinnah]

The back lock only does well because the cable goes around the lock bar and effectively holds the lock closed. They had the same issue last time. The handle failed because all The hanging weight was over the lockbar.

I don't believe this is true.

If you stop the video at 11:02, 11:15, and 11:28, you can see the pivot pin just forward of the cable. This means that the cable couldn't be stopping the lock bar from lifting, as it the only part that lifts up above the frame is well forward of the pivot pin.

Now, had they used some other lock back, with a longer lock bar and pivot pin much further back from the blade pivot, then yes... putting the cable 1" from the blade pivot would have put the cable on the front of lock bar, effectively holding it in place.

This was my first concern when I heard about the test and spent some time stopping and stopping the video to double check.

 

[B.F.U]

I didn't quote you, I was replying to the person who answered you.

You redacted your post and understandably so - I didnt insult you nor the test, so there is no need for any of us to get our collective knickers in a bunch

I said, that I did find the test interesting and indeed entertaining and you are certainly entitled to finding any test perfectly valid.

But folders are folders - not fixed blades. With sensible folding knife use, I just dont see these forces being applied as an issue. If you use any knife as intended, You should be cutting away from you. Of course a lock can fail, as You say.

As for who should use slipjoints exclusively - my retort would be, that if one intends to bring that kind of pressure (which you talk about) on a folding knife, maybe one would be better off with a fixed blade exclusively

How ever, I dont intend to get into a mud slinging match over this. There is a slight possibility, that I simply dont take the tests nor spine whacking too serious nor as the holy gospel and/or and indicator of how hard I should use MY knives. You on the other hand are free to interpret them as You please, thats your perogative.

Caveat: I think we can both agree, that having the strongest lock possible is a good thing. See, there is some common ground

I'm just saying that I always see the "if you're putting pressure on the spine you are using a knife wrong, you cut with the edge/away from you. Maybe you should use a fixed blade exclusively." argument all the time, and my response to that is that anyone who uses a knife is going to sometimes make a mistake in some fashion. That fashion might be slipping during a tough cut and putting pressure on the spine, and it is not difficult to exert 50+ pounds of pressure. And, as the antithesis of the "if you make mistakes maybe you should only use a fixed blade" argument, I say if you use a knife perfectly and never make mistakes maybe you should only use a slipjoint.

Sometimes it's difficult to separate the two when looking at a quote of something one says, but I wasn't criticising you at all, just showing my disagreement with the content of your post and highlighting how the same logic could be used in the other direction.

I do believe someone is more likely to make the occasional mistake that makes them appreciate a good lock that doesn't slip or deform under less than 100 pounds of pressure than they are to never make a mistake while using a knife.

 

[Lee48]

Sometimes you just need a fixed blade.

 

[Zero_Time]

But folders are folders - not fixed blades. With sensible folding knife use, I just dont see these forces being applied as an issue. If you use any knife as intended, You should be cutting away from you. Of course a lock can fail, as You say.

As for who should use slipjoints exclusively - my retort would be, that if one intends to bring that kind of pressure (which you talk about) on a folding knife, maybe one would be better off with a fixed blade exclusively

How ever, I dont intend to get into a mud slinging match over this. There is a slight possibility, that I simply dont take the tests nor spine whacking too serious nor as the holy gospel and/or and indicator of how hard I should use MY knives. You on the other hand are free to interpret them as You please, thats your perogative.

Caveat: I think we can both agree, that having the strongest lock possible is a good thing. See, there is some common ground

It all depends on what you think a folding knife can or should be used for.

If you think it's for cutting apples, then yeah, a slipjoint is sufficient.

If you want it for opening packages that are small, moderate lock may be good.

If you break down tons of boxes at a time, then you probably want a robust folder because you can easily screw up and end up getting the knife stuck, necessitating cutting towards you. Ditto for woodwork.

And, if you think that a folding knife can or should be able to be used to cut PEOPLE, well, then everything from spine whacks to pressure to wiggling side to side while stabbing and all sorts of "abuse" can happen.

So, maybe a fixed blade should be used, but you're not legal or it's a hassle to carry one, so you carry a folder.

There's plenty of good reasons for a folder that can hold up to weird knife "abuse". It might just be that some people don't use knives the same way.

Zero

 

[Scurvy092]

I'm having a hard time of thinking of a scenario where I'm going to put a large load on the lock.

The only thing I can think of is wedging the blade and the instead of wiggling it loose and continuing the cut you slam down in the handle even harder. But that just seems dumb to me.

 

[B.F.U]

Again, maybe some people don't make mistakes while cutting or don't cut the kind of things that take force to cut through. I do, and sometimes those mistakes have a good bit of force behind them being that I'm a very large person, so I appreciate a lock that is reliable.

 

[Sonnydaze]

I liked the test. Was surprised that the FRN held up so well. Thanks for all of your work, BladeHQ.
Don

 

[B.F.U]

I liked the test. Was surprised that the FRN held up so well. Thanks for all of your work, BladeHQ.
Don

I agree, it's great to have a dealer that will honestly compare and destroy their stock for more knowledge (and exposure).

I think FRN is great.

 

[BladeScout]

I didn't quote you, I was replying to the person who answered you.

Technically correct You quoted Scurvy who agreed with my statement in a one syllable word, but no harm no foul....and certainly no problem

I'm just saying that I always see the "if you're putting pressure on the spine you are using a knife wrong, you cut with the edge/away from you. Maybe you should use a fixed blade exclusively." argument all the time

Maybe thats because you keep telling knife geeks to use slipjoints exclusively (Im KIDDING!)

and my response to that is that anyone who uses a knife is going to sometimes make a mistake in some fashion.

Agreed.
Mistakes with knives can and will happen.

Sometimes it's difficult to separate the two when looking at a quote of something one says, but I wasn't criticising you at all, just showing my disagreement with the content of your post and highlighting how the same logic could be used in the other direction.

No problem. We are having a civilized debate. You contribute just fine here on the forum and I respect a lot of your writings. All is good

I do believe someone is more likely to make the occasional mistake that makes them appreciate a good lock that doesn't slip or deform under less than 100 pounds of pressure than they are to never make a mistake while using a knife.

Good point.

 

[BladeScout]

.....

It all depends on what you think a folding knife can or should be used for.
I agree

If you think it's for cutting apples, then yeah, a slipjoint is sufficient.
Yup

If you want it for opening packages that are small, moderate lock may be good.
Certainly
If you break down tons of boxes at a time, then you probably want a robust folder because you can easily screw up and end up getting the knife stuck, necessitating cutting towards you. Ditto for woodwork.
My go to cardboard box shredders are two Opinels, which I cut down (ring lock removed) and they work fine, but on principle I agree. Ditto for woodworking.

And, if you think that a folding knife can or should be able to be used to cut PEOPLE, well, then everything from spine whacks to pressure to wiggling side to side while stabbing and all sorts of "abuse" can happen.
You didnt specify SD, so Im going with the following; for knife fighting, a fixed knife should be used, but thats PracTac territory
So, maybe a fixed blade should be used, but you're not legal or it's a hassle to carry one, so you carry a folder.
No doubt, that there are those forced to adopt that mindset because of legalities or other factors, I agree
There's plenty of good reasons for a folder that can hold up to weird knife "abuse". It might just be that some people don't use knives the same way.
Sure.
Zero