Endura 4 Lock Failure

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Vivi

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I was out beginning the durability portion of my Endura comparison test. I started out whacking the stock E4 through the piece of wood I was working on, though it mostly dealt with rotted chunks on the exterior. The reprofiled ZDP189 was given a long workout, through tougher wood. You can see me having trouble even pulling it free because of the tension the wood was putting on it. My technique was sloppy, but I was still surprised when the knife broke. I expected to lose a mm or two of tip or maybe get a bend in the edge, but not to snap the lock.

Video link http://www.youtube.com/watch?v=iy0TTtVISTc

Not really sure how hitting the bottom of the handle made the lock break?
 
I watched the vid several times, and all I could come up with is a guess. By hitting the bottom of the handle you created an impulse or impact that went through the flexible handle into the rocksolid blade. This impulse caused an compression, which forced the locking part of the blade to fail. The impact could only "escape" by destroying it, because the energy had to go somewhere. I think that all handles are more prone to failure if you hit the handle, especially its bottom. Does that makes any sense..?

After all, sad to see that you lost a knife. I just purchased an Endura ZDP-189 on the bay some hours ago. Thanks for the vid!
 
I know that others will disagree, but I do not believe that a folder like an Endura should be expected to survive that kind of abuse.

So saying that the lock "failed" is IMO somewhat inaccurate. Might be better to say that you broke it.

JMO. :)
 
powernoodle said:
I know that others will disagree, but I do not believe that a folder like an Endura should be expected to survive that kind of abuse.

So saying that the lock "failed" is IMO somewhat inaccurate. Might be better to say that you broke it.

JMO. :)
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I'd agree with that, Slamming a pocket knife through a piece of wood, is kinda like racing a bus down the quarter mile, it'll do it, but dont be surprised if it shits itself in the process.
 
powernoodle said:
I know that others will disagree, but I do not believe that a folder like an Endura should be expected to survive that kind of abuse.

So saying that the lock "failed" is IMO somewhat inaccurate. Might be better to say that you broke it.

JMO. :)
Click to expand...

I've done this before with Enduras, Delicas, a UKPK and a Byrd Cara Cara. I have footage of the VG10 Endura handling this just fine. I've done this for years without ever breaking a lock. I wish I knew for sure why this Endura broke, but as you can see it at least appears to take all the batoning just fine. The handle smack at the end seemed to do it in, but from all I could observe the batoning did little to it.

Regardless, I wouldn't of been too surprised if it broke during the batoning. It's not something I'd expect any folder to survive indefinitely. What caught me off guard was breaking the lock on an upwards handle hit.

I'm not really concerned with terminology. I have a broken knife and I'm not 100% sure why it's broken, would be cool if I could find out somehow. Not gonna say what I did to it had nothing to do with it "failing" though. :p

Morales, enjoy the knife. It's a very nice one.

*sigh* this was supposed to be an edge durability test, not a lock test. :rolleyes:
 
mmmotorcycle said:
Ever heard of a fixed blade? :D
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I know you're just joking around, but just so everyone is aware for future reference....

This wasn't intentional at all, this was meant to test the edge not the lock. I've done this before and the other Endura I did this with today worked fine for it. If I ever baton something out of necessity I use a large kuhkuri, not a folder. This was not representative of what I typically use my Enduras for.
 
that is just like an "over strike" (swinging at something and hitting the front of the handle". Overstriking does not usually break small light blades, but in this case the blade has held wedged in place.
 
Ever heard of a fixed blade

But that super duper duper ZDPxyz superb magic steel should handle anything thing that others can
 
greater said:
Ever heard of a fixed blade

But that super duper duper ZDPxyz superb magic steel should handle anything thing that others can
Click to expand...

This wasn't intentional at all, this was meant to test the edge not the lock. I've done this before and the other Endura I did this with today worked fine for it. If I ever baton something out of necessity I use a large kuhkuri, not a folder. This was not representative of what I typically use my Enduras for.
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I wonder how many times I'm going to hear this?

But yeah, the ZDP189 did show some excellent edge holding so far. Unless the people at Spyderco are interested in taking a look at this I still plan to do the edge retention testing. I also thought it was cool how I reprofiled it flat to the stone, giving it a scandi grind with a light microbevel, and the blade held up to batoning without any issues. So that begs the question, what durability do you gain out of the thick edge? What do people do thats tougher on an edge than batoning through wood that they want that kind of an edge?

[youtube]_Nz0PKM-vV0[/youtube]
 
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I agree, for a knife that typically sees such work, ZDP189 is not at the top of my list. That's not what I was testing for though.
 
kidwholaughs said:
Seems like improper tempering during the heat treat. That some how caused brittleness around the lock.
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I wonder if this is the case? ZDP189 is usually promoted as a very high hardness steel. I would not be surprised to find it significantly more brittle than other stainless steels run several HRc points lower.
 
it looks to me like it broke right at the point where the round hole is in the corner of the cutout, it could be simply a manufacturing defect, a tiny crack or imperfection in the steel that spread while you were hitting the knife. It appears that the hit that broke it was not very hard, but simply the straw that broke the camel's back. ZDP is a very hard steel and this does not surprise me any more than s30v fixed blade knives snapping under impacts and lateral pressure. Harder steels will almost always be more brittle. the technology has come a long way toward making steels that are very hard and still maintain good toughness but if you intend to baton/hammer or pry with a knife you would be better off with a slightly softer/tougher steel
 
Yikes!
I'm not sure that any folder is designed for batoning of any sort. You'd have to be really careful to get away with it.
Most of the time when people mention batoning with a folder, they say it's best to disengage the lock, that way you won't get the result seen in the video.
 
Joshua J. said:
Most of the time when people mention batoning with a folder, they say it's best to disengage the lock, that way you won't get the result seen in the video.
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Thats the way I was taught to do it and the only safe and responsible way I've ever heard it explained. Knife locks may or may not stand up to repeated sharp and heavy spine impact but they are certainly not designed for it.
 
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